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http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#NewLISP
NewLISP
(let (a (array 10 10)) (dotimes (i 10) (dotimes (j 10) (setf (a i j) (rand 21)))) (catch (dotimes (i 10) (dotimes (j 10) (print (a i j)) (print " ") (if (= 20 (a i j)) (throw))))))
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Perl
Perl
foreach my $i (@collection) { print "$i\n"; }
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Phix
Phix
sequence s = {-2,"field",3.14159268979,{"this","that"}} for i=1 to length(s) do ?s[i] end for
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#K
K
so: {+/x@2*!_ceil(#x)%2} se: {+/{+/0$'$x}'2*x@1+2*!(#x)%2} luhn: {n:|0$'$x; 0=((se n)+so n)!10}
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#Sidef
Sidef
func is_mersenne_prime(p) { return true if (p == 2) var s = 4 var M = (2**p - 1) { s = powmod(s, 2, M)-2 } * (p-2) s == 0 }   Inf.times {|n| if (n.is_prime && is_mersenne_prime(n)) { say "M#{n}" } }
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LiveCode
LiveCode
repeat forever put "SPAM" & return end repeat
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Logo
Logo
forever [print "SPAM]
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#langur
langur
var .i = 1024 while .i > 0 { writeln .i .i \= 2 }
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lasso
Lasso
local(i = 1024) while(#i > 0) => {^ #i + '\r' #i /= 2 ^}
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lambdatalk
Lambdatalk
  {def downward_for {lambda {:i} {if {< :i 0} then (end of loop) else :i {downward_for {- :i 1}}}}} -> downward_for   {downward_for 10} -> 10 9 8 7 6 5 4 3 2 1 0 (end of loop)  
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#Frink
Frink
n = 0 do { n = n + 1 println[n] } while n mod 6 != 0
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#Delphi
Delphi
program LoopFor;   {$APPTYPE CONSOLE}   var i, j: Integer; begin for i := 1 to 5 do begin for j := 1 to i do Write('*'); Writeln; end; end.
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Frink
Frink
  for a = 1 to 100 step 5 println[a]  
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#NewLISP
NewLISP
(for (i 0 10) (print i) (unless (= i 10) (print ", ")))
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Nim
Nim
var s = "" for i in 1..10: s.add $i if i == 10: break s.add ", " echo s
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Nim
Nim
import random, strutils   const ArrSize = 10   var a: array[ArrSize, array[ArrSize, int]] var s = ""   randomize() # Different results each time this runs.   # Initialize using loops on items rather than indexes. for row in a.mitems: for item in row.mitems: item = rand(1..20)   block outer: # Loop using indexes. for i in 0..<ArrSize: for j in 0..<ArrSize: if a[i][j] < 10: s.add(' ') addf(s, "$#", $a[i][j]) if a[i][j] == 20: break outer s.add(", ") s.add('\n')   echo s
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#NS-HUBASIC
NS-HUBASIC
10 DIM A(20) 20 FOR I=1 TO 20 30 A(I)=RND(20)+1 40 NEXT 50 PRINT "THE FULL LIST:"; 60 FOR I=1 TO 20 70 PRINT A(I); 80 NEXT 90 PRINT 100 PRINT "THE FULL LIST UP TO THE FIRST ";"INSTANCE OF 20:"; 110 FOR I=1 TO 20 120 PRINT A(I); 130 IF A(I)=20 THEN END 140 NEXT
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PHL
PHL
var numbers = 1..10;   numbers each # (number) [ printf("%i\n", number); ];
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PHP
PHP
foreach ($collect as $i) { echo "$i\n"; }   foreach ($collect as $key => $i) { echo "\$collect[$key] = $i\n"; }
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#Kotlin
Kotlin
// version 1.0   fun checkLuhn(number: String): Boolean { var isOdd = true var sum = 0   for (index in number.indices.reversed()) { val digit = number[index] - '0' sum += if (isOdd) digit else (digit * 2).let { (it / 10) + (it % 10) } isOdd = !isOdd }   return (sum % 10) == 0 }   fun main(args: Array<String>) { val numbers = arrayOf("49927398716", "49927398717", "1234567812345678", "1234567812345670") for (number in numbers) println("${number.padEnd(16)} is ${if(checkLuhn(number)) "valid" else "invalid"}") }
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#Swift
Swift
func lucasLehmer(_ p: Int) -> Bool { let m = BigInt(2).power(p) - 1 var s = BigInt(4)   for _ in 0..<p-2 { s = ((s * s) - 2) % m }   return s == 0 }   for prime in Eratosthenes(upTo: 70) where lucasLehmer(prime) { let m = Int(pow(2, Double(prime))) - 1   print("2^\(prime) - 1 = \(m) is prime") }
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LOLCODE
LOLCODE
HAI CAN HAS STDIO? IM IN YR LOOP VISIBLE "SPAM" IM OUTTA YR LOOP KTHXBYE
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lua
Lua
  while true do print("SPAM") end   --Another solution repeat print("SPAM") until false  
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Liberty_BASIC
Liberty BASIC
i = 1024 while i > 0 print i i = int( i / 2) wend end
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LIL
LIL
set num 1024; while {$num > 0} {print $num; set num [expr $num \ 2]}
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#langur
langur
for .i in 10..0 { writeln .i }
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lasso
Lasso
loop(-from=10, -to=0, -by=-1) => {^ loop_count + ' ' ^}
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#FutureBasic
FutureBasic
window 1   dim as long i   do i++ print i until ( i mod 6 == 0 )   HandleEvents
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#Diego
Diego
set_ns(rosettacode);   add_var({str},s)_value(); add_var({str},output);   add_for({int},i)_from(1)_uptoand(5)_inc() with_var(s)_v(); add_for({int},j)_from(0)_upto([i])_inc() with_var(s)_calc([s]&="*");  ; with_var(output)_calc(&=[s]&\n); ;   me_msg([output]);   reset_ns[];
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#GAP
GAP
for i in [1, 3 .. 11] do Print(i, "\n"); od;   1 3 5 7 9 11  
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#NS-HUBASIC
NS-HUBASIC
10 FOR I=1 TO 10 20 PRINT I; 30 IF I=10 THEN GOTO 50 40 PRINT ","; 50 NEXT
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Objeck
Objeck
  bundle Default { class Hello { function : Main(args : String[]) ~ Nil { for(i := 1; true; i += 1;) { i->Print(); if(i = 10) { break; }; ", "->Print(); }; '\n'->Print(); } } }  
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#OCaml
OCaml
$ ocaml   # Random.self_init();; - : unit = ()   # let m = Array.make_matrix 10 10 0 ;; val m : int array array = [|[|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]; [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0|]|]   # for i = 0 to pred 10 do for j = 0 to pred 10 do m.(i).(j) <- 1 + Random.int 20 done; done;; - : unit = ()   # try for i = 0 to pred 10 do for j = 0 to pred 10 do Printf.printf " %d" m.(i).(j); if m.(i).(j) = 20 then raise Exit; done; print_newline() done; with Exit -> print_newline() ;; 15 8 15 9 9 6 1 18 6 18 17 1 13 15 13 1 16 4 13 9 15 3 5 19 17 3 1 11 5 2 1 1 6 19 20 - : unit = ()
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PicoLisp
PicoLisp
(mapc println '(Apple Banana Coconut))
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Pike
Pike
int main(){ array(int|string) collect = ({109, "Hi", "asdf", "qwerty"}); foreach(collect, int|string elem){ write(elem + "\n"); } }
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#langur
langur
val .luhntest = f(.s) { val .t = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9] val .numbers = s2n .s val .oddeven = len(.numbers) rem 2   for[=0] .i of .numbers { _for += if(.i rem 2 == .oddeven: .numbers[.i]; .t[.numbers[.i]+1]) } div 10 }   val .tests = h{ "49927398716": true, "49927398717": false, "1234567812345678": false, "1234567812345670": true, }   for .key of .tests { val .pass = .luhntest(.key) write .key, ": ", .pass writeln if(.pass == .tests[.key]: ""; " (LUHN TEST FAILED)") }
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#Tcl
Tcl
proc main argv { set n 0 set t [clock seconds] show_mersenne 2 [incr n] t   for {set p 3} {$p <= [lindex $argv 0]} {incr p 2} { if {![prime $p]} continue if {[LucasLehmer $p]} { show_mersenne $p [incr n] t } } } proc show_mersenne {p n timevar} { upvar 1 $timevar time set now [clock seconds] puts [format "%2d: %5ds M%s" $n [expr {$now - $time}] $p] set time $now } proc prime i { if {$i in {2 3}} {return 1} prime0 $i [expr {int(sqrt($i))}] } proc prime0 {i div} { expr {!($i % $div)? 0: $div <= 2? 1: [prime0 $i [incr div -1]]} } proc LucasLehmer p { set mp [expr {2**$p-1}] set s 4 for {set i 2} {$i < $p} {incr i} { set s [expr {($s**2 - 2) % $mp}] } expr {$s == 0} }   main 33218
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#M2000_Interpreter
M2000 Interpreter
  Module CheckIt { Print "SPAM" loop } Checkit  
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#M4
M4
define(`spam',`SPAM spam') spam
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lingo
Lingo
n = 1024 repeat while n>0 put n n = n/2 -- integer division implicitely returns floor: 1/2 -> 0 end repeat
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lisaac
Lisaac
+ i : INTEGER; i := 1024; { i > 0 }.while_do { i.println;   i := i / 2; };
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lhogho
Lhogho
for "i [10 0] [print :i]
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lingo
Lingo
repeat with i = 10 down to 0 put i end repeat
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#Gambas
Gambas
Public Sub Main() Dim siCount As Short   Repeat Inc siCount Print siCount;; Until siCount Mod 6 = 0   End
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#DMS
DMS
number i, j for (i = 1; i <= 5; i++) { for (j = 1; j <= i; j++) { Result( "*" ) } Result( "\n" ) }
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#GML
GML
for(i = 0; i < 10; i += 2) show_message(string(i))
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#OCaml
OCaml
let last = 10 in for i = 1 to last do print_int i; if i <> last then print_string ", "; done; print_newline();
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Oforth
Oforth
: loopn | i | 10 loop: i [ i dup print 10 ifEq: [ break ] "," . ] printcr ;
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Octave
Octave
function search_almost_twenty() % create a 100x100 matrix... m = unifrnd(0,20, 100,100); for i = 1:100 for j = 1:100 disp( m(i,j) ) if ( abs(m(i,j) - 20) < 1e-2 ) return endif endfor endfor endfunction   search_almost_twenty()   % avoiding function, we need a control variable. m = unifrnd(0,20, 100,100); innerloopbreak = false; for i = 1:100 for j = 1:100 disp( m(i,j) ) if ( abs(m(i,j) - 20) < 1e-2 ) innerloopbreak = true; break; endif endfor if ( innerloopbreak ) break; endif endfor
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PL.2FI
PL/I
declare A(10) fixed binary; do i = lbound(A,1) to hbound(A,1); put skip list (A(i)); end;
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Plain_English
Plain English
To run: Start up. Create a list. Write each entry in the list to the console. Destroy the list. Wait for the escape key. Shut down.   An entry is a thing with a number.   A list is some entries.   To add a number to a list: Allocate memory for an entry. Put the number into the entry's number. Append the entry to the list.   To create a list: Add 1 to the list. Add 2 to the list. Add 3 to the list. Add 6 to the list. Add 7 to the list. Add 9 to the list.   To write an entry to the console: Convert the entry's number to a string. Write the string to the console.   To write each entry in a list to the console: Get an entry from the list. Loop. If the entry is nil, exit. Write the entry to the console. Put the entry's next into the entry. Repeat.
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#Lasso
Lasso
#!/usr/bin/lasso9   define luhn_check(number) => { local( rev = #number->asString, checksum = 0 ) #rev->reverse iterate(#rev, local(digit)) => { if((loop_count % 2) == 0) => { #checksum += (2 * integer(#digit)) integer(#digit) >= 5 ? #checksum -= 9 else #checksum += integer(#digit) } } (#checksum % 10) != 0 ? return false return true }   stdoutnl(luhn_check(49927398716)) // true stdoutnl(luhn_check(49927398717)) // false stdoutnl(luhn_check(1234567812345678)) // false stdoutnl(luhn_check(1234567812345670)) // true
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#TI-83_BASIC
TI-83 BASIC
19→M 1→N For(E,2,M) If E=2 Then:0→S Else:4→S End (N+1)*2-1→N For(I,1,E-2) Reminder(S*S-2,N)→S End If S=0 Then:Disp E End End
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Make
Make
spam: @echo SPAM $(MAKE)
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Malbolge
Malbolge
  bP&A@?>=<;:9876543210/.-,+*)('&%$T"!~}|;]yxwvutslUSRQ.yx+i)J9edFb4`_^]\yxwRQ)(TSRQ]m!G0KJIyxFvDa%_@?"=<5:98765.-2+*/.-,+*)('&%$#"!~}|utyrqvutsrqjonmPkjihgfedc\DDYAA\>>Y;;V886L5322G//D,,G))>&&A##!7~5:{y7xvuu,10/.-,+*)('&%$#"yb}|{zyxwvutmVqSohmOOjihafeHcEa`YAA\[ZYRW:U7SLKP3NMLK-I,GFED&%%@?>=6;|9y70/4u210/o-n+k)"!gg$#"!x}`{zyxZvYtsrqSoRmlkjLhKfedcEaD_^]\>Z=XWVU7S6QPON0LKDI,GFEDCBA#?"=};438y6543s1r/o-&%*k('&%e#d!~}|^z]xwvuWsVqponPlOjihgIeHcba`B^A\[ZY;W:UTSR4PI2MLKJ,,AFE(&B;:?"~<}{zz165v3s+*/pn,mk)jh&ge#db~a_{^\xwvoXsrqpRnmfkjMKg`_GG\aDB^A?[><X;9U86R53ONM0KJC,+FEDC&A@?!!6||3876w4-tr*/.-&+*)('&%$e"!~}|utyxwvutWlkponmlOjchg`edGba`_XW\?ZYRQVOT7RQPINML/JIHAFEDC&A@?>!<;{98yw5.-ss*/pn,+lj(!~ff{"ca}`^z][wZXtWUqTRnQOkNLhgfIdcFaZ_^A\[Z<XW:U8SRQPOHML/JIHG*ED=%%:?>=~;:{876w43210/(-,+*)('h%$d"ca}|_z\rqYYnsVTpoRPledLLafIGcbE`BXW??TY<:V97S64P31M0.J-+G*(DCB%@?"=<;|98765.3210p.-n+$)i'h%${"!~}|{zyxwvuXVlkpSQmlOjLbafIGcbE`BXW??TY<:V97S64P31M0.J-+G*(D'%A@?"=<}:98y6543,1r/.o,+*)j'&%eez!~a|^tsx[YutWUqjinQOkjMhJ`_dGEaDB^A?[><X;9U86R53O20LKJ-HG*ED'BA@?>7~;:{y7x5.3210q.-n+*)jh&%$#"c~}`{z]rwvutWrkpohmPkjihafI^cba`_^A\[>YXW:UTS5QP3NM0KJ-HGF?D'BA:?>=~;:z8765v32s0/.-nl$#(ig%fd"ca}|_]yrqvYWsVTpSQmPNjMKgJHdGEa`_B]\?ZY<WVUTMR5PO20LK.IHA))>CB%#?87}}49zx6wu3tr0qo-nl*ki'hf$ec!~}`{^yxwvotsrUponQlkMihKIe^]EEZ_B@\?=Y<:V97S64P31M0.J-+GFE(C&A@?8=<;:{876w43s10qo-&%kk"'hf$ec!b`|_]y\ZvYWsVTpSQmlkNiLgf_dcba`C^]\?ZY;WV97SLK33HM0.J-+G*(D'%A$">!};|z8yw543t1r/(-,+*)(i&%fd"!~}|_t]xwvutslqTonmPkjLhKIeHFbEC_^A?[TSX;9UT7R4JIN1/K.,H+)E(&B%#?"~<}{987x/4ussr).o,+l)(h&ge#db~a_{^\x[YutWrTjinQOkNLhgJeG]\aDB^]@[=SRW:877LQP3N0FEJ-+**?DC&A#98=~|:98yx/4u21rp(',mk)(ig%|{"ca}`^z][wZXtWUqTRnQOkNLhKIedcFE`YB@@?ZYRW:UTS6QPO11F..CHGF)(CB;@#>!~;XzV7gwu-QrrqMoJIkZF'WC$#AbQ`_{^L9wI64"VDConzl+j);JJ%qGFEZ~}]{ygwRuc8aSq44"H1Y.iV,e*RQ  
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LiveCode
LiveCode
put 1024 into n repeat while n > 0 put n & cr divide n by 2 end repeat
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Logo
Logo
make "n 1024 while [:n > 0] [print :n make "n :n / 2]
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lisaac
Lisaac
10.downto 0 do { i : INTEGER; i.println;   };
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LiveCode
LiveCode
local x=10 repeat for 10 times put x & return add -1 to x end repeat
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#GAP
GAP
n := 0; repeat n := n + 1; Print(n, "\n"); until RemInt(n, 6) = 0;
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#GML
GML
i = 0 do { i += 1 show_message(string(i)) } until (i mod 6 = 0)
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#dodo0
dodo0
fun for -> var, test, body, return # define a for loop using recursion ( test(var) -> continue if (continue) -> ( body(var) -> var for (var, test, body, return) ) | return(var) ) | for   fun upToFive (-> index, return) '<='(index, 5, return) | upToFive   for (1, upToFive) -> index, return ( fun countTheStars -> stars, return ( 'count'(stars) -> n '<'(n, index, return) # continue until n = index ) | countTheStars   for ("*", countTheStars) -> prefix, return 'str'(prefix, "*", return) | stars   println(stars) ->   'inc'(index, return) ) | result exit()
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Go
Go
for i := 1; i < 10; i += 2 { fmt.Printf("%d\n", i) }
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Oz
Oz
  for N in {List.number 1 10 1} break:Break do {System.printInfo N} if N == 10 then {Break} end {System.printInfo ", "} end
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Panda
Panda
array{{1..10}}.join(',')
http://rosettacode.org/wiki/Longest_increasing_subsequence
Longest increasing subsequence
Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.
#11l
11l
F longest_increasing_subsequence(x) V n = x.len V P = [0] * n V M = [0] * (n + 1) V l = 0 L(i) 0 .< n V lo = 1 V hi = l L lo <= hi V mid = (lo + hi) I/ 2 I (x[M[mid]] < x[i]) lo = mid + 1 E hi = mid - 1 V newl = lo P[i] = M[newl - 1] M[newl] = i   I (newl > l) l = newl   [Int] s V k = M[l] L(i) (l - 1 .. 0).step(-1) s.append(x[k]) k = P[k] R reversed(s)   L(d) [[3, 2, 6, 4, 5, 1], [0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15]] print(‘a L.I.S. of #. is #.’.format(d, longest_increasing_subsequence(d)))
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#OoRexx
OoRexx
numbers = .array~new() do i = 1 to 10 do j = 1 to 10 numbers[i,j] = random(1, 20) end end   do i = 1 to numbers~dimension(1) do j = 1 to numbers~dimension(2) say numbers[i,j] if numbers[i,j] = 20 then leave i end end
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Pop11
Pop11
lvars el, lst = [1 2 3 4 foo bar]; for el in lst do printf(el,'%p\n'); endfor;
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PostScript
PostScript
[1 5 3 2] { = } forall (abc) { = } forall
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#Liberty_BASIC
Liberty BASIC
' [RC] Luhn test   card$(1)="49927398716" card$(2)="49927398717" card$(3)="1234567812345678" card$(4)="1234567812345670"   for test = 1 to 4 odd=1 sum = 0 for n = len(card$(test)) to 1 step -1 num=val(mid$(card$(test),n,1)) if odd then sum = sum + num odd=0 else num=num*2 if num<=9 then sum = sum + num else sum = sum + val(left$(str$(num),1)) + val(right$(str$(num),1)) end if odd=1 end if next if sum mod 10 = 0 then print card$(test),"True" else print card$(test),"False" end if next
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#uBasic.2F4tH
uBasic/4tH
m = 15 n = 1 For j = 2 To m If j = 2 Then s = 0 Else s = 4 EndIf n = (n + 1) * 2 - 1 For i = 1 To j - 2 s = (s * s - 2) % n Next i If s = 0 Then Print "M";j Next
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Maple
Maple
  > do print(SPAM) end;  
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
While[True, Print@"SPAM"; ]
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#LOLCODE
LOLCODE
HAI 1.3   I HAS A n ITZ 1024   IM IN YR LOOP UPPIN YR nop WILE n VISIBLE n n R QUOSHUNT OF n AN 2 IM OUTTA YR LOOP   KTHXBYE
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lua
Lua
n = 1024 while n>0 do print(n) n = math.floor(n/2) end
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Logo
Logo
for [i 10 0] [print :i]
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Lua
Lua
  for i=10,0,-1 do print(i) end  
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#Go
Go
package main   import "fmt"   func main() { var value int for { value++ fmt.Println(value) if value%6 != 0 { break } } }
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#Draco
Draco
proc nonrec main() void: byte i,j; for i from 1 upto 5 do for j from 1 upto i do write("*") od; writeln() od corp
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Groovy
Groovy
for(i in (2..9).step(2)) { print "${i} " } println "Who do we appreciate?"
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PARI.2FGP
PARI/GP
n=0; while(1, print1(n++); if(n>9, break); print1(", ") );
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Pascal
Pascal
program numlist(output);   const MAXNUM: integer = 10; var i: integer;   begin { loop 1: w/ if branching } for i := 1 to MAXNUM do begin write(i); if i <> MAXNUM then write(', ') end; writeln; { loop 2: w/o if branching } for i := 1 to MAXNUM-1 do write(i, ', '); writeln(MAXNUM); end.
http://rosettacode.org/wiki/Longest_increasing_subsequence
Longest increasing subsequence
Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.
#360_Assembly
360 Assembly
* Longest increasing subsequence 04/03/2017 LNGINSQ CSECT USING LNGINSQ,R13 base register B 72(R15) skip savearea DC 17F'0' savearea STM R14,R12,12(R13) save previous context ST R13,4(R15) link backward ST R15,8(R13) link forward LR R13,R15 set addressability LA R6,1 i=1 DO WHILE=(CH,R6,LE,=H'2') do i=1 to 2 IF CH,R6,EQ,=H'1' THEN if i=1 then MVC N,=AL2((A2-A1)/2) n=hbound(a1) MVC AA(64),A1 a=a1 ELSE , else MVC N,=AL2((AA-A2)/2) n=hbound(a2) MVC AA(64),A2 a=a2 ENDIF , endif MVC PG,=CL80': ' init buffer LA R2,AA-2 @a LH R3,N n BAL R14,PRINT print a MVC LL,=H'0' l=0 SR R7,R7 j=0 DO WHILE=(CH,R7,LE,N) do j=0 to n MVC LO,=H'1' lo=1 MVC HI,LL hi=l LH R4,LO lo DO WHILE=(CH,R4,LE,HI) do while lo<=hi LH R1,LO lo AH R1,HI lo+hi SRA R1,1 /2 STH R1,MIDDLE middle=(lo+hi)/2 SLA R1,1 *2 LH R1,MM(R1) m(middle+1) SLA R1,1 *2 LH R3,AA(R1) r3=a(m(middle+1)+1) LR R1,R7 j SLA R1,1 *2 LH R4,AA(R1) r4=a(j+1) LH R2,MIDDLE middle IF CR,R3,LT,R4 THEN if a(m(middle+1)+1)<a(j+1) then LA R2,1(R2) middle+1 STH R2,LO lo=middle+1 ELSE , else BCTR R2,0 middle-1 STH R2,HI hi=middle-1 ENDIF , endif LH R4,LO lo ENDDO , end /*while*/ LH R10,LO newl=lo LR R1,R10 newl SLA R1,1 *2 LH R3,MM-2(R1) m(newl) LR R1,R7 j SLA R1,1 *2 STH R3,PP(R1) p(j+1)=m(newl) LR R1,R10 newl SLA R1,1 *2 STH R7,MM(R1) m(newl+1)=j IF CH,R10,GT,LL if newl>l then STH R10,LL l=newl ENDIF , endif LA R7,1(R7) j++ ENDDO , enddo j LH R1,LL l SLA R1,1 *2 LH R10,MM(R1) k=m(l+1) LH R7,LL j=l DO WHILE=(CH,R7,GE,=H'1') do j=l to 1 by -1 LR R1,R10 k SLA R1,1 *2 LH R2,AA(R1) a(k+1) LR R1,R7 j SLA R1,1 *2 STH R2,SS-2(R1) s(j)=a(k+1) LR R1,R10 k SLA R1,1 *2 LH R10,PP(R1) k=p(k+1) BCTR R7,0 j-- ENDDO , enddo j MVC PG,=CL80'> ' init buffer LA R2,SS-2 @s LH R3,LL l BAL R14,PRINT print a LA R6,1(R6) i++ ENDDO , enddo i L R13,4(0,R13) restore previous savearea pointer LM R14,R12,12(R13) restore previous context XR R15,R15 rc=0 BR R14 exit PRINT LA R10,PG ---- print subroutine LA R10,2(R10) pgi=2 LA R7,1 j=1 DO WHILE=(CR,R7,LE,R3) do j=1 to nx LR R1,R7 j SLA R1,1 *2 LH R1,0(R2,R1) x(j) XDECO R1,XDEC edit x(j) MVC 0(3,R10),XDEC+9 output x(j) LA R10,3(R10) pgi+=3 LA R7,1(R7) j++ ENDDO , enddo j XPRNT PG,L'PG print buffer BR R14 ---- return A1 DC H'3',H'2',H'6',H'4',H'5',H'1' A2 DC H'0',H'8',H'4',H'12',H'2',H'10',H'6',H'14' DC H'1',H'9',H'5',H'13',H'3',H'11',H'7',H'15' AA DS 32H a(32) PP DS 32H p(32) MM DS 32H m(32) SS DS 32H s(32) N DS H n LL DS H l LO DS H lo HI DS H hi MIDDLE DS H middle PG DS CL80 buffer XDEC DS CL12 temp for xdeco YREGS END LNGINSQ
http://rosettacode.org/wiki/Loops/Continue
Loops/Continue
Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#11l
11l
L(i) 1..10 I i % 5 == 0 print(i) L.continue print(i, end' ‘, ’)
http://rosettacode.org/wiki/Longest_common_substring
Longest common substring
Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string.   This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string  (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff  (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction
#11l
11l
F longest_common_substring(s1, s2) V ir = 0 V jr = -1 L(i1) 0 .< s1.len V? i2 = s2.find(s1[i1]) L i2 != N V (j1, j2) = (i1, i2) L j1 < s1.len & j2 < s2.len & s2[j2] == s1[j1] I j1 - i1 >= jr - ir (ir, jr) = (i1, j1) j1++ j2++ i2 = s2.find(s1[i1], i2 + 1) R s1[ir..jr]   print(longest_common_substring(‘thisisatest’, ‘testing123testing’))
http://rosettacode.org/wiki/Loops/Nested
Loops/Nested
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Oz
Oz
declare fun {CreateMatrix Width Height} Matrix = {List.make Height} in for Row in Matrix do Row = {List.make Width} for X in Row do X = {OS.rand} mod 20 +1 end end Matrix end   proc {PrintMatrix Matrix} %% print until we see 20 for Row in Matrix break:OuterBreak do for X in Row do {Show X} if X == 20 then {OuterBreak} end end end end in {PrintMatrix {CreateMatrix 10 10}}
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#PowerShell
PowerShell
  $colors = "Black","Blue","Cyan","Gray","Green","Magenta","Red","White","Yellow", "DarkBlue","DarkCyan","DarkGray","DarkGreen","DarkMagenta","DarkRed","DarkYellow"   foreach ($color in $colors) { Write-Host "$color" -ForegroundColor $color }  
http://rosettacode.org/wiki/Loops/Foreach
Loops/Foreach
Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Prolog
Prolog
?- foreach(member(X, [red,green,blue,black,white]), writeln(X)). red green blue black white true.  
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers
Luhn test of credit card numbers
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks   SEDOL   ISIN
#LiveCode
LiveCode
function LuhnTest cc local s1,evens, s2 repeat with n = 1 to len(cc) if n mod 2 is not 0 then add (char -n of cc) to s1 else put (char -n of cc) * 2 into evens if evens > 9 then subtract 9 from evens add evens to s2 end if end repeat return the last char of (s1 + s2) is 0 end LuhnTest   -- test repeat for each item ccno in "49927398716,49927398717,1234567812345678,1234567812345670" put ccno && LuhnTest(ccno) & cr after luhncheck end repeat put luhncheck   49927398716 true 49927398717 false 1234567812345678 false 1234567812345670 true  
http://rosettacode.org/wiki/Lucas-Lehmer_test
Lucas-Lehmer test
Lucas-Lehmer Test: for p {\displaystyle p} an odd prime, the Mersenne number 2 p − 1 {\displaystyle 2^{p}-1} is prime if and only if 2 p − 1 {\displaystyle 2^{p}-1} divides S ( p − 1 ) {\displaystyle S(p-1)} where S ( n + 1 ) = ( S ( n ) ) 2 − 2 {\displaystyle S(n+1)=(S(n))^{2}-2} , and S ( 1 ) = 4 {\displaystyle S(1)=4} . Task Calculate all Mersenne primes up to the implementation's maximum precision, or the 47th Mersenne prime   (whichever comes first).
#VBScript
VBScript
iexpmax = 15 n=1 out="" For iexp = 2 To iexpmax If iexp = 2 Then s = 0 Else s = 4 End If n = (n + 1) * 2 - 1 For i = 1 To iexp - 2 s = (s * s - 2) Mod n Next If s = 0 Then out=out & "M" & iexp & " " End If Next Wscript.echo out
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#MATLAB_.2F_Octave
MATLAB / Octave
while true fprintf('SPAM\n') end
http://rosettacode.org/wiki/Loops/Infinite
Loops/Infinite
Task Print out       SPAM       followed by a   newline   in an infinite loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Maxima
Maxima
do(disp("SPAM"));
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#M2000_Interpreter
M2000 Interpreter
  Module Checkit { Def long A=1024 While A>0 { Print A A/=2 } } Checkit  
http://rosettacode.org/wiki/Loops/While
Loops/While
Task Start an integer value at   1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreachbas   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#m4
m4
divert(-1)   define(`loop', `ifelse(eval(0 < ($1)),1,`$1` 'loop(eval(($1) / 2))')')   divert`'dnl loop(1024)dnl
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#M2000_Interpreter
M2000 Interpreter
  For i=1 to 10 step 2 : Print i : Next i  
http://rosettacode.org/wiki/Loops/Downward_for
Loops/Downward for
Task Write a   for   loop which writes a countdown from   10   to   0. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#M4
M4
define(`for', `ifelse($#,0,``$0'', `ifelse(eval($2 $3),1, `pushdef(`$1',$2)$5`'popdef(`$1')$0(`$1',eval($2+$4),$3,$4,`$5')')')')dnl   for(`x',`10',`>=0',`-1',`x ')
http://rosettacode.org/wiki/Loops/Do-while
Loops/Do-while
Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference Do while loop Wikipedia.
#Groovy
Groovy
def i = 0 do { i++ println i } while (i % 6 != 0)
http://rosettacode.org/wiki/Loops/For
Loops/For
“For”   loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges Reference For loop Wikipedia.
#Dragon
Dragon
for (i = 0, i < 5, i++) { for (j = 0, j <= i, j++) { show "*" } showln "" }
http://rosettacode.org/wiki/Loops/For_with_a_specified_step
Loops/For with a specified step
Task Demonstrate a   for-loop   where the step-value is greater than one. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Haskell
Haskell
import Control.Monad (forM_) main = do forM_ [2,4..8] (\x -> putStr (show x ++ ", ")) putStrLn "who do we appreciate?"
http://rosettacode.org/wiki/Loops/N_plus_one_half
Loops/N plus one half
Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks   Loop over multiple arrays simultaneously   Loops/Break   Loops/Continue   Loops/Do-while   Loops/Downward for   Loops/For   Loops/For with a specified step   Loops/Foreach   Loops/Increment loop index within loop body   Loops/Infinite   Loops/N plus one half   Loops/Nested   Loops/While   Loops/with multiple ranges   Loops/Wrong ranges
#Peloton
Peloton
<@ FORLITLIT>10|<@ SAYPOSFOR>...</@><@ ABF>,</@></@>