Loops/Foreach: Difference between revisions

← Older edit
Content deleted Content added
Aartaka (talk | contribs)
129 edits
Add ed example
 
(236 intermediate revisions by more than 100 users not shown)
Line 1: Line 1:
{{task|Iteration}}
{{task|Iteration}}
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.
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]]
<br><br>

=={{header|11l}}==
{{trans|C#}}

<syntaxhighlight lang="11l">V things = [‘Apple’, ‘Banana’, ‘Coconut’]

L(thing) things
print(thing)</syntaxhighlight>


=={{header|ACL2}}==
=={{header|ACL2}}==


<lang Lisp>(defun print-list (xs)
<syntaxhighlight lang="lisp">(defun print-list (xs)
(if (endp xs)
(if (endp xs)
nil
nil
(prog2$ (cw "~x0~%" (first xs))
(prog2$ (cw "~x0~%" (first xs))
(print-list (rest xs)))))</lang>
(print-list (rest xs)))))</syntaxhighlight>


<pre>
<pre>
Line 18: Line 47:
SYM
SYM
NIL
NIL
</pre>

=={{header|Action!}}==
In Action! there is no for-each loop.
<syntaxhighlight lang="action!">PROC Main()
DEFINE PTR="CARD"
BYTE i
PTR ARRAY items(10)
items(0)="First" items(1)="Second"
items(2)="Third" items(3)="Fourth"
items(4)="Fifth" items(5)="Sixth"
items(6)="Seventh" items(7)="Eighth"
items(8)="Ninth" items(9)="Tenth"

PrintE("In Action! there is no for-each loop")
PutE()
FOR i=0 TO 9
DO
PrintE(items(i))
OD
RETURN</syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Foreach.png Screenshot from Atari 8-bit computer]
<pre>
In Action! there is no for-each loop

First
Second
Third
Fourth
Fifth
Sixth
Seventh
Eighth
Ninth
Tenth
</pre>
</pre>


=={{header|Ada}}==
=={{header|Ada}}==
===arrays===
===arrays===
<lang Ada>with Ada.Integer_Text_IO;
<syntaxhighlight lang="ada">with Ada.Integer_Text_IO;
use Ada.Integer_Text_IO;
use Ada.Integer_Text_IO;


Line 32: Line 97:


for Num in A'Range loop
for Num in A'Range loop
put( A (Num) );
Put( A (Num) );
end loop;
end loop;


end For_Each;</lang>
end For_Each;</syntaxhighlight>

Alternative solution (Ada 2012):

<syntaxhighlight lang="ada"> for Item of A loop
Put( Item );
end loop;</syntaxhighlight>

===doubly linked lists===
===doubly linked lists===
{{works with|Ada 2005}}
{{works with|Ada 2005}}
<lang Ada>with Ada.Integer_Text_IO, Ada.Containers.Doubly_Linked_Lists;
<syntaxhighlight lang="ada">with Ada.Integer_Text_IO, Ada.Containers.Doubly_Linked_Lists;
use Ada.Integer_Text_IO, Ada.Containers;
use Ada.Integer_Text_IO, Ada.Containers;


Line 62: Line 134:
DL_List.Iterate (Print_Node'Access);
DL_List.Iterate (Print_Node'Access);
end Doubly_Linked_List;</lang>
end Doubly_Linked_List;</syntaxhighlight>
===vectors===
===vectors===
{{works with|Ada 2005}}
{{works with|Ada 2005}}
<lang Ada>with Ada.Integer_Text_IO, Ada.Containers.Vectors;
<syntaxhighlight lang="ada">with Ada.Integer_Text_IO, Ada.Containers.Vectors;
use Ada.Integer_Text_IO, Ada.Containers;
use Ada.Integer_Text_IO, Ada.Containers;


Line 89: Line 161:
V.Iterate (Print_Element'Access);
V.Iterate (Print_Element'Access);
end Vector_Example;</lang>
end Vector_Example;</syntaxhighlight>


=={{header|Aikido}}==
=={{header|Aikido}}==
Aikido's <code>foreach</code> loop allows iteration through multiple value types.
Aikido's <code>foreach</code> loop allows iteration through multiple value types.
===strings===
===strings===
<lang aikido>var str = "hello world"
<syntaxhighlight lang="aikido">var str = "hello world"
foreach ch str { // you can also use an optional 'in'
foreach ch str { // you can also use an optional 'in'
println (ch) // one character at a time
println (ch) // one character at a time
}</lang>
}</syntaxhighlight>
===vectors===
===vectors===
<lang aikido>var vec = [1,2,3,4]
<syntaxhighlight lang="aikido">var vec = [1,2,3,4]
foreach v vec { // you can also use an optional 'in'
foreach v vec { // you can also use an optional 'in'
println (v)
println (v)
}</lang>
}</syntaxhighlight>
===maps===
===maps===
<lang aikido>var cities = {"San Ramon": 50000, "Walnut Creek": 70000, "San Francisco": 700000} // map literal
<syntaxhighlight lang="aikido">var cities = {"San Ramon": 50000, "Walnut Creek": 70000, "San Francisco": 700000} // map literal
foreach city cities {
foreach city cities {
println (city.first + " has population " + city.second)
println (city.first + " has population " + city.second)
}</lang>
}</syntaxhighlight>
===integers===
===integers===
<lang aikido>foreach i 100 {
<syntaxhighlight lang="aikido">foreach i 100 {
println (i) // prints values 0..99
println (i) // prints values 0..99
}
}
Line 121: Line 193:
foreach i a..b {
foreach i a..b {
println (i) // prints values from a to b (20..10)
println (i) // prints values from a to b (20..10)
}</lang>
}</syntaxhighlight>
===Objects===
===Objects===
Aikido allows definition of a <code>foreach</code> operator for an object. In this example we define a single linked list and a foreach operator to iterate through it
Aikido allows definition of a <code>foreach</code> operator for an object. In this example we define a single linked list and a foreach operator to iterate through it
<lang aikido>class List {
<syntaxhighlight lang="aikido">class List {
class Element (public data) {
class Element (public data) {
public var next = null
public var next = null
Line 157: Line 229:
foreach n list {
foreach n list {
println (n)
println (n)
}</lang>
}</syntaxhighlight>
===Coroutines===
===Coroutines===
Aikido supports coroutines. The foreach operator may be used to iterate thorough the generated values.
Aikido supports coroutines. The foreach operator may be used to iterate thorough the generated values.
<lang aikido>// coroutine to generate the squares of a sequence of numbers
<syntaxhighlight lang="aikido">// coroutine to generate the squares of a sequence of numbers
function squares (start, end) {
function squares (start, end) {
for (var i = start ; i < end ; i++) {
for (var i = start ; i < end ; i++) {
Line 172: Line 244:
foreach s squares (start, end) {
foreach s squares (start, end) {
println (s)
println (s)
}</lang>
}</syntaxhighlight>
===Files===
===Files===
If you open a file you can iterate through all the lines
If you open a file you can iterate through all the lines
<lang aikido>var s = openin ("input.txt")
<syntaxhighlight lang="aikido">var s = openin ("input.txt")
foreach line s {
foreach line s {
print (line)
print (line)
}</lang>
}</syntaxhighlight>
===Enumerations===
===Enumerations===
<lang aikido>enum Color {
<syntaxhighlight lang="aikido">enum Color {
RED, GREEN, BLUE
RED, GREEN, BLUE
}
}
Line 186: Line 258:
foreach color Color {
foreach color Color {
println (color)
println (color)
}</lang>
}</syntaxhighlight>

=={{header|Aime}}==
<syntaxhighlight lang="aime"># iterate over a list of integers
integer i, v;

for (i, v in list(2, 3, 5, 7, 11, 13, 17, 18)) {
}</syntaxhighlight>


=={{header|ALGOL 68}}==
=={{header|ALGOL 68}}==
Line 192: Line 271:
{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}}
{{works with|ALGOL 68G|Any - tested with release mk15-0.8b.fc9.i386}}
{{works with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386}}
{{works with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386}}
<lang algol68>[]UNION(STRING, INT, PROC(REF FILE)VOID) collection = ("Mary","Had",1,"little","lamb.",new line);
<syntaxhighlight lang="algol68">[]UNION(STRING, INT, PROC(REF FILE)VOID) collection = ("Mary","Had",1,"little","lamb.",new line);


FOR index FROM LWB collection TO UPB collection DO
FOR index FROM LWB collection TO UPB collection DO
print((collection[index]," "))
print((collection[index]," "))
OD</lang>
OD</syntaxhighlight>
Output:
Output:
<pre>
<pre>
Mary Had +1 little lamb.
Mary Had +1 little lamb.
</pre>
</pre>
<br>
Note: [[ALGOL 68S]] actually has a reserved word FOREACH that is used to break arrays in to portions, and process in parallel.
[[ALGOL 68S]] has a reserved word FOREACH that is used to break arrays in to portions, and process in parallel.
<br>
<br>[[ALGOL 68RS]] and [[Algol68toc]] have a FORALL loop, the following is equivalent to the example above:
<syntaxhighlight lang="algol68">FORALL c IN collection DO
print((c," "))
OD</syntaxhighlight>

=={{header|Amazing Hopper}}==
<syntaxhighlight lang="c">
#include <jambo.h>

Main
things = {}, len list=0
Set ' 100,200,300,"Hello world!", -3,-2,-1 ' Apndlist 'things'
Let ' len list := Length(things) '
Printnl ' "\nNormal count:\n" '
For each( n, things, len list )
Printnl ' "Thing : ", n '
Next

Printnl ' "\n\nReverse count:\n" '
For each reverse ( n, things, len list )
Printnl ' "Thing : ", n '
Next
End
</syntaxhighlight>
{{out}}
<pre>
Normal count:

Thing : 100
Thing : 200
Thing : 300
Thing : Hello world!
Thing : -3
Thing : -2
Thing : -1


Reverse count:

Thing : -1
Thing : -2
Thing : -3
Thing : Hello world!
Thing : 300
Thing : 200
Thing : 100

</pre>


=={{header|AmigaE}}==
=={{header|AmigaE}}==
<lang amigae>PROC main()
<syntaxhighlight lang="amigae">PROC main()
DEF a_list : PTR TO LONG, a
DEF a_list : PTR TO LONG, a
a_list := [10, 12, 14]
a_list := [10, 12, 14]
Line 212: Line 342:
-> if the "action" fits a single statement, we can do instead
-> if the "action" fits a single statement, we can do instead
ForAll({a}, a_list, `WriteF('\d\n', a))
ForAll({a}, a_list, `WriteF('\d\n', a))
ENDPROC</lang>
ENDPROC</syntaxhighlight>

=={{header|Apex}}==
<syntaxhighlight lang="apex">
Integer[] myInts = new Integer[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

for (Integer i : myInts) {
System.debug(i);
}
</syntaxhighlight>

=={{header|AppleScript}}==
<syntaxhighlight lang="applescript">repeat with fruit in {"Apple", "Orange", "Banana"}
log contents of fruit
end repeat</syntaxhighlight>

=={{header|Arturo}}==
<syntaxhighlight lang="rebol">arr: ["one" "two" "three"]

dict: #[
name: "John"
surname: "Doe"
age: 34
]

loop arr 'item ->
print item

loop dict [key val]->
print [key "=>" val]</syntaxhighlight>
{{out}}
<pre>one
two
three
name => John
surname => Doe
age => 34</pre>


=={{header|AutoHotkey}}==
=={{header|AutoHotkey}}==
<lang AutoHotkey>string = mary,had,a,little,lamb
<syntaxhighlight lang="autohotkey">string = mary,had,a,little,lamb
Loop, Parse, string, `,
Loop, Parse, string, `,
MsgBox %A_LoopField%</lang>
MsgBox %A_LoopField%</syntaxhighlight>


=={{header|AWK}}==
=={{header|AWK}}==
The <code>for (element_index in array)</code> can be used, but it does not give elements' indexes in the order inside the array (AWK indexes in array are indeed more like hashes).
The <code>for (element_index in array)</code> can be used, but it does not give elements' indexes in the order inside the array (AWK indexes in array are indeed more like hashes).
<lang awk>BEGIN {
<syntaxhighlight lang="awk">
BEGIN {
split("Mary had a little lamb", strs, " ")
split("Mary had a little lamb", strs, " ")
for(el in strs) {
for(el in strs) {
print strs[el]
print strs[el]
}
}
}</lang>
}</syntaxhighlight>
If elements must be returned in some order, keys must be generated in that order; in the example above the array is filled through the split function, which uses indexes from 1, so to iterate over the array's elements in the ''right'' order, a normal loop can be done:
If elements must be returned in some order, keys must be generated in that order.
In the example above the array is filled through the split function,
<lang awk>for(i=1; i <= length(strs); i++) {
which uses indexes from 1.
print strs[i]
So to iterate over the array's elements in the ''right'' order,
}</lang>
a normal loop can be used:
<syntaxhighlight lang="awk">BEGIN {
n = split("Mary had a little lamb", strs, " ")
for(i=1; i <= n; i++) {
print strs[i]
}
}</syntaxhighlight>


Note that in awk, foreach loops can only be performed against an associative container. It is not possible to loop against an explicit list, so the following will not work:
Note that in awk, foreach loops can only be performed against an associative container.
It is not possible to loop against an explicit list, so the following will not work:


<lang awk># This will not work
<syntaxhighlight lang="awk"># This will not work
BEGIN {
BEGIN {
for (l in "apples","bananas","cherries") {
for (el in "apples","bananas","cherries") {
print "I like " l
print "I like " el
}
}</lang>
}</syntaxhighlight>

=={{header|Bait}}==
`for-in` loops work with both builtin container types (arrays and maps).
They allow to iterate the indices/keys and values.

<syntaxhighlight lang="bait">
fun for_in_array() {
arr := ['1st', '2nd', '3rd']

// Iterate over array indices and elements
for i, val in arr {
println('${i}: ${val}')
}

// Using only one variable will iterate over the elements
for val in arr {
println(val)
}

// To only iterate over the indices, use `_` as the second variable name.
// `_` is a special variable that will ignore any assigned value
for i, _ in arr {
println(i)
}
}

fun for_in_map() {
nato_abc := map{
'a': 'Alpha'
'b': 'Bravo'
'c': 'Charlie'
'd': 'Delta'
}

// Iterate over map keys and values.
// Note that, unlike arrays, only the two-variable variant is allowed
for key, val in nato_abc {
println('${key}: ${val}')
}
}

fun main() {
for_in_array()
println('')
for_in_map()
}
</syntaxhighlight>

=={{header|BASIC}}==

==={{header|BaCon}}===
BaCon includes support for ''delimited strings''. Delimited strings form a type of collection. Along with this support is a <code>for in</code> loop. Not quite a <code>for each</code> but pretty close.

<syntaxhighlight lang="freebasic">OPTION COLLAPSE TRUE
FOR x$ IN "Hello cruel world"
PRINT x$
NEXT

FOR y$ IN "1,2,\"3,4\",5" STEP ","
PRINT y$
NEXT</syntaxhighlight>

{{out}}
<pre>prompt$ bacon -q forin.bac >/dev/null
prompt$ ./forin
Hello
cruel
world
1
2
"3,4"
5</pre>

The <code>OPTION COLLAPSE TRUE</code> statements prevents empty results when multiple delimiters appear together. The default delimiter is space, and can be changed with <code>OPTION DELIM x</code> where x is a static string literal.


=={{header|BASIC256}}==
==={{header|BASIC256}}===
BASIC-256 does not have a FOR EACH type statement. Use a FOR loop to iterate through an array by index.
BASIC-256 does not have a FOR EACH type statement. Use a FOR loop to iterate through an array by index.
<lang BASIC256>DIM collection$(1)
<syntaxhighlight lang="basic256">DIM collection$(1)
collection$ = { "The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog." }
collection$ = { "The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog." }


Line 248: Line 498:
PRINT collection$[i]+ " ";
PRINT collection$[i]+ " ";
NEXT i
NEXT i
PRINT</lang>
PRINT</syntaxhighlight>
Output:
Output:
<pre>The quick brown fox jumps over the lazy dog.</pre>
<pre>The quick brown fox jumps over the lazy dog.</pre>


=={{header|BBC BASIC}}==
==={{header|BBC BASIC}}===
{{works with|BBC BASIC for Windows}}
{{works with|BBC BASIC for Windows}}
<lang bbcbasic> DIM collection$(8)
<syntaxhighlight lang="bbcbasic"> DIM collection$(8)
collection$() = "The", "quick", "brown", "fox", "jumps", \
collection$() = "The", "quick", "brown", "fox", "jumps", \
\ "over", "the", "lazy", "dog."
\ "over", "the", "lazy", "dog."
Line 261: Line 511:
PRINT collection$(index%) " ";
PRINT collection$(index%) " ";
NEXT
NEXT
PRINT</lang>
PRINT</syntaxhighlight>

==={{header|Commodore BASIC}}===
Commodore BASIC too does not have a FOR-EACH construct. FOR loop is used to iterate through a string array by index. READ-DATA is used to fill up the string array
<syntaxhighlight lang="qbasic">10 DIM A$(9) :REM DECLARE STRING ARRAY
20 REM *** FILL ARRAY WITH WORDS ***
30 FOR I = 0 TO 8
40 READ A$(I)
50 NEXT
60 REM *** PRINT ARRAY CONTENTS ***
70 FOR I = 0 TO 8
80 PRINT A$(I)" ";
90 NEXT
100 END
1000 DATA THE, QUICK, BROWN, FOX, JUMPS, OVER, THE, LAZY, DOG.</syntaxhighlight>

==={{header|Creative Basic}}===
<syntaxhighlight lang="creative basic">DEF AnArray[11]:INT

AnArray=0,1,2,3,4,5,6,7,8,9,10

'A console only program will work without OPENCONSOLE and
'CLOSECONSOLE; however, it does not hurt to use them.
OPENCONSOLE

FOR X=0 TO 10
PRINT AnArray[X]
NEXT X

'keep the console from closing right away.
DO:UNTIL INKEY$<>""

CLOSECONSOLE

'because this is a console only program.
END
</syntaxhighlight>

==={{header|FreeBASIC}}===
<syntaxhighlight lang="freebasic">' FB 1.05.0

' FreeBASIC doesn't have a foreach loop but it's easy to manufacture one using macros

#Macro ForEach(I, A)
For _i as integer = LBound(A) To UBound(A)
#Define I (A(_i))
#EndMacro

#Define In ,

Dim a(-5 To 5) As Integer = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}
ForEach(i in a)
Print i; " ";
Next

Print
Sleep</syntaxhighlight>

{{out}}
<pre>
1 2 3 4 5 6 7 8 9 10 11
</pre>

==={{header|Gambas}}===
'''[https://gambas-playground.proko.eu/?gist=cb94500c68749f6f93915f3f10de5a03 Click this link to run this code]'''
<syntaxhighlight lang="gambas">Public Sub Main()
Dim siInput As Short[] = [1, 8, 0, 6, 4, 7, 3, 2, 5, 9]
Dim siTemp As Short

For Each siTemp In siInput.Sort()
Print siTemp;;
Next

End</syntaxhighlight>
{{out}}
<pre>
0 1 2 3 4 5 6 7 8 9
</pre>

==={{header|IS-BASIC}}===
<syntaxhighlight lang="is-basic">100 STRING COLLECTION$(1 TO 9)*8
110 LET I=1
120 DO
130 READ IF MISSING EXIT DO:COLLECTION$(I)
140 LET I=I+1
150 LOOP
160 FOR J=1 TO I-1
170 PRINT COLLECTION$(J);" ";
180 NEXT
190 DATA The,quick,brown,fox,jumps,over,the,lazy,dog.</syntaxhighlight>

==={{header|IWBASIC}}===
'''Linked List'''
<syntaxhighlight lang="iwbasic">DEF AList:POINTER

AList=ListCreate()

'Add items to the list.
DEF X:INT

FOR X=0 TO 10
POINTER Temp=ListAdd(AList,NEW(INT,1))
#<INT>temp=X
'The hash ("#") dereferencing operator is unique to IWBASIC and Creative Basic, and
'it is suitable for most basic pointer needs. IWBASIC also supports a "C style"
'dereferencing operator: "*". And that will work here too.
NEXT X

'A program compiled as console only does not need the commands to open and
'close the console. However, it does not hurt to use them.
OPENCONSOLE

'***Iterate the list with the "for each" loop***
FOR Temp=EACH AList AS INT
PRINT #Temp
NEXT

PRINT

'A press any key to continue message is automatic in a program compiled as a console only
program. I presume the compiler inserts the code.
CLOSECONSOLE

'Because this is a console only program.
END</syntaxhighlight>

'''An Array'''
<syntaxhighlight lang="iwbasic">DEF AnArray[11]:INT

AnArray=0,1,2,3,4,5,6,7,8,9,10

OPENCONSOLE

FOR X=0 TO 10
PRINT AnArray[X]
NEXT X

PRINT

'a press any key message is automatic when compiled as console only.
CLOSECONSOLE

'Because this is a console only program.
END
</syntaxhighlight>

==={{header|Lambdatalk}}===
<syntaxhighlight lang="scheme">
{def collection alpha beta gamma delta}
-> collection

{S.map {lambda {:i} {br}:i} {collection}}
->
alpha
beta
gamma
delta

or

{def S.foreach
{lambda {:s}
{if {S.empty? {S.rest :s}}
then {S.first :s}
else {S.first :s} {br}{S.foreach {S.rest :s}}}}}

{S.foreach {collection}}
->
alpha
beta
gamma
delta

</syntaxhighlight>

==={{header|Liberty BASIC}}===
The most natural way is to use a csv list with a sentinel value.
<syntaxhighlight lang="lb">in$ ="Not,Hardly,Just,Adequately,Quite,Really,Very,Fantastically,xyzzy"
element$ =""
i =1 ' used to point to successive elements

do
element$ =word$( in$, i, ",")
if element$ ="xyzzy" then exit do
print element$; " good!"
i =i +1
loop until 1 =2

end</syntaxhighlight>
Not good!
Hardly good!
Just good!
Adequately good!
Quite good!
Really good!
Very good!
Fantastically good!

==={{header|NS-HUBASIC}}===
<syntaxhighlight lang="ns-hubasic">10 DIM A$(9) : REM DECLARE STRING ARRAY
20 REM ADD DATA TO ARRAY AND PRINT ARRAY CONTENTS
30 FOR I=0 TO 8
40 READ A$(I)
50 PRINT A$(I)" ";
60 NEXT
70 DATA THE, QUICK, BROWN, FOX, JUMPS, OVER, THE, LAZY, DOG.</syntaxhighlight>

==={{header|PureBasic}}===
Works for LinkedLists and Maps
<syntaxhighlight lang="purebasic">ForEach element()
PrintN(element())
Next</syntaxhighlight>

==={{header|Run BASIC}}===
<syntaxhighlight lang="runbasic">t$={Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday"

while word$(t$,i+1,",") <> ""
i = i + 1
print word$(t$,i,",")
wend</syntaxhighlight>

==={{header|TI-89 BASIC}}===
<syntaxhighlight lang="ti89b">Local i,strs
Define strs = {"Lorem","ipsum","dolor"}
For i, 1, dim(strs)
Disp strs[i]
EndFor</syntaxhighlight>

==={{header|VBA}}===
<syntaxhighlight lang="vb">Public Sub LoopsForeach()
Dim FruitArray() As Variant
Dim Fruit As Variant
FruitArray = [{"Apple","Banana","Strawberry"}]
Dim FruitBasket As Collection
Set FruitBasket = New Collection
For Each Fruit In FruitArray
FruitBasket.Add Fruit
Next Fruit
For Each Fruit In FruitBasket
Debug.Print Fruit
Next Fruit
End Sub</syntaxhighlight>

==={{header|VBScript}}===
<syntaxhighlight lang="vbscript">items = Array("Apple", "Orange", "Banana")

For Each x In items
WScript.Echo x
Next</syntaxhighlight>

==={{header|Visual Basic .NET}}===
<syntaxhighlight lang="vbnet">Dim list As New List(Of String)
list.Add("Car")
list.Add("Boat")
list.Add("Train")
For Each item In list
Console.WriteLine(item)
Next</syntaxhighlight>


==={{header|Yabasic}}===
<syntaxhighlight lang="yabasic">//Yabasic tampoco tiene una construcción ForEach.
//Mediante un bucle FOR iteramos a través de una matriz por índice.
//READ-DATA se usa para rellenar la matriz

dim arreglo(10)
data 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
for each = 0 to arraysize(a(),1)
read arreglo(each)
next each

for each = 0 to arraysize(a(),1)
print arreglo(each), " ";
next each
print
end</syntaxhighlight>


=={{header|Batch File}}==
The FOR command can imitate the "Foreach Loop". The whitespace and the comma (,) are the default delimiters.<br>

'''Direct usage:'''
<syntaxhighlight lang="dos">@echo off
for %%A in (This is a sample collection) do (
echo %%A
)</syntaxhighlight>
'''Using a Collection Variable:'''
<syntaxhighlight lang="dos">@echo off
set "collection=This is a sample collection"
for %%A in (%collection%) do (
echo %%A
)</syntaxhighlight>
{{Out|They have the Same Output}}
<pre>This
is
a
sample
collection</pre>

=={{header|bc}}==
There is no "for each"-loop in bc. For accessing each element of an array (the only collection-like type) one uses a straightforward for-loop.
<syntaxhighlight lang="bc">a[0] = .123
a[1] = 234
a[3] = 95.6
for (i = 0; i < 4; i++) {
a[i]
}</syntaxhighlight>


=={{header|Bracmat}}==
=={{header|Bracmat}}==
Bracmat has a more or less traditional 'while' loop (<code>whl'<i>expression</i></code>) which was introduced rather late in the history of Bracmat. Before that, tail recursion was a way to repeat something.
Bracmat has a more or less traditional 'while' loop (<code>whl'<i>expression</i></code>) which was introduced rather late in the history of Bracmat. Before that, tail recursion was a way to repeat something.
But let us make a list first:
But let us make a list first:
<lang bracmat> ( list
<syntaxhighlight lang="bracmat"> ( list
= Afrikaans
= Afrikaans
Ελληνικά
Ελληνικά
Line 272: Line 829:
മലയാളം
മലയാളം
ئۇيغۇرچە
ئۇيغۇرچە
)</lang>
)</syntaxhighlight>
The 'while' solution. Use an auxiliary variable <code>L</code> that gets its head chopped off until nothing is left:
The 'while' solution. Use an auxiliary variable <code>L</code> that gets its head chopped off until nothing is left:
<lang bracmat> !list:?L
<syntaxhighlight lang="bracmat"> !list:?L
& whl'(!L:%?language ?L&out$!language)</lang>
& whl'(!L:%?language ?L&out$!language)</syntaxhighlight>
The tail-recursive solution. When the auxiliary variable is reduced to nothing, the loop fails. By adding the <code>~</code> flag to the initial invocation, failure is turned into success. This solution benefits from tail recursion optimization.
The tail-recursive solution. When the auxiliary variable is reduced to nothing, the loop fails. By adding the <code>~</code> flag to the initial invocation, failure is turned into success. This solution benefits from tail recursion optimization.
<lang bracmat> !list:?L
<syntaxhighlight lang="bracmat"> !list:?L
& ( loop
& ( loop
= !L:%?language ?L
= !L:%?language ?L
Line 283: Line 840:
& !loop
& !loop
)
)
& ~!loop</lang>
& ~!loop</syntaxhighlight>
A completly different way of iteration is by using a pattern that matches an element in the list, does something useful as a side effect and then fails, forcing bracmat to backtrack and try the next element in the list. The <code>@</code> flag matches at most one element. The <code>%</code> flag matches at least one element. Together they ensure that exactly one language name is assigned to the variable <code>language</code>. After all elements have been done, control is passed to the rhs of the <code>|</code> operator.
A completely different way of iteration is by using a pattern that matches an element in the list, does something useful as a side effect and then fails, forcing bracmat to backtrack and try the next element in the list. The <code>@</code> flag matches at most one element. The <code>%</code> flag matches at least one element. Together they ensure that exactly one language name is assigned to the variable <code>language</code>. After all elements have been done, control is passed to the rhs of the <code>|</code> operator.
<lang bracmat> ( !list
<syntaxhighlight lang="bracmat"> ( !list
: ? (%@?language&out$!language&~) ?
: ? (%@?language&out$!language&~) ?
|
|
)</lang>
)</syntaxhighlight>


=={{header|C}}==
=={{header|C}}==
C does not really have a native 'container' type, nor does it have a 'for each' type statement. The following shows how to loop through an array and print each element.
C does not really have a native 'container' type, nor does it have a 'for each' type statement. The following shows how to loop through an array and print each element.
<lang c>#include <stdio.h>
<syntaxhighlight lang="c">#include <stdio.h>
...
...


Line 301: Line 858:
for(ix=0; ix<LIST_SIZE; ix++) {
for(ix=0; ix<LIST_SIZE; ix++) {
printf("%s\n", list[ix]);
printf("%s\n", list[ix]);
}</lang>
}</syntaxhighlight>


The C language does, however, have a number of standard data structures that can be thought of as collections, and foreach can easily be made with a macro.<BR><BR>
The C language does, however, have a number of standard data structures that can be thought of as collections, and foreach can easily be made with a macro.<BR><BR>


C string as a collection of char
C string as a collection of char
<syntaxhighlight lang="c">
<lang c>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
Line 324: Line 881:
return(0);
return(0);
}
}
</syntaxhighlight>
</lang>


C int array as a collection of int (array size known at compile-time)
C int array as a collection of int (array size known at compile-time)
<syntaxhighlight lang="c">
<lang c>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
Line 344: Line 901:
return(0);
return(0);
}
}
</syntaxhighlight>
</lang>


Most general: string or array as collection (collection size known at run-time)
Most general: string or array as collection (collection size known at run-time)
: ''Note: idxtype can be removed and [http://gcc.gnu.org/onlinedocs/gcc/Typeof.html typeof(col[0])] used in it's place with [[GCC]]''
: ''Note: idxtype can be removed and [http://gcc.gnu.org/onlinedocs/gcc/Typeof.html typeof(col&#91;0&#93;)] can be used in it's place with [[GCC]]''
<syntaxhighlight lang="c">
<lang c>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
Line 373: Line 930:
return(0);
return(0);
}
}
</syntaxhighlight>
</lang>

=={{header|C sharp|C#}}==
<syntaxhighlight lang="csharp">string[] things = {"Apple", "Banana", "Coconut"};

foreach (string thing in things)
{
Console.WriteLine(thing);
}</syntaxhighlight>


=={{header|C++}}==
=={{header|C++}}==
C++03 did not have a "for each" loop. The following is a generic loop which works with any standard container except for built-in arrays. The code snippet below assumes that the container type in question is typedef'd to <tt>container_type</tt> and the actual container object is named container.
C++03 did not have a "for each" loop. The following is a generic loop which works with any standard container except for built-in arrays. The code snippet below assumes that the container type in question is typedef'd to <tt>container_type</tt> and the actual container object is named container.
<lang cpp>for (container_type::iterator i = container.begin(); i != container.end(); ++i)
<syntaxhighlight lang="cpp">for (container_type::iterator i = container.begin(); i != container.end(); ++i)
{
{
std::cout << *i << "\n";
std::cout << *i << "\n";
}</lang>
}</syntaxhighlight>
However the idiomatic way to output a container would be
However the idiomatic way to output a container would be
<lang cpp>std::copy(container.begin(), container.end(),
<syntaxhighlight lang="cpp">std::copy(container.begin(), container.end(),
std::output_iterator<container_type::value_type>(std::cout, "\n"));</lang>
std::ostream_iterator<container_type::value_type>(std::cout, "\n"));</syntaxhighlight>
There's also an algorithm named <tt>for_each</tt>. However, you need a function or function object to use it, e.g.
There's also an algorithm named <tt>for_each</tt>. However, you need a function or function object to use it, e.g.
<lang cpp>void print_element(container_type::value_type const& v)
<syntaxhighlight lang="cpp">void print_element(container_type::value_type const& v)
{
{
std::cout << v << "\n";
std::cout << v << "\n";
Line 391: Line 956:


...
...
std::for_each(container.begin(), container.end(), print_element);</lang>
std::for_each(container.begin(), container.end(), print_element);</syntaxhighlight>
{{works with|C++11}}
{{works with|C++11}}
<syntaxhighlight lang="cpp">for (auto element: container)
<lang cpp>#include <iterator_concepts>

for (auto element: container)
{
{
std::cout << element << "\n";
std::cout << element << "\n";
}</lang>
}</syntaxhighlight>
Here <tt>container</tt> is the container variable, <tt>element</tt> is the loop variable (initialized with each container element in turn), and auto means that the compiler should determine the correct type of that variable automatically. If the type is expensive to copy, a const reference can be used instead:
Here <tt>container</tt> is the container variable, <tt>element</tt> is the loop variable (initialized with each container element in turn), and auto means that the compiler should determine the correct type of that variable automatically. If the type is expensive to copy, a const reference can be used instead:
<syntaxhighlight lang="cpp">for (auto const& element: container)
<lang cpp>#include <iterator_concepts>

for (auto const& element: container)
{
{
std::cout << element << "\n";
std::cout << element << "\n";
}</lang>
}</syntaxhighlight>
Of course the container elements can also be changed by using a non-const reference (provided the container isn't itself constant).
Of course the container elements can also be changed by using a non-const reference (provided the container isn't itself constant):
<syntaxhighlight lang="cpp">for (auto&& element: container) //use a 'universal reference'
{
element += 42;
}</syntaxhighlight>


=={{header|C sharp|C#}}==
=={{header|C3}}==
C3 has a standard built-in foreach for iterating through lists.
<lang csharp>string[] things = {"Apple", "Banana", "Coconut"};


<syntaxhighlight lang="c3">String[] fruits = { "Apple", "Banana", "Strawberry" };
foreach (string thing in things)
foreach (fruit : fruits) io::printn(fruit);</syntaxhighlight>
{

Console.WriteLine(thing);
=={{header|Chapel}}==
}</lang>
<syntaxhighlight lang="chapel">var food = ["Milk", "Bread", "Butter"];
for f in food do writeln(f);</syntaxhighlight>


=={{header|Clojure}}==
=={{header|Clojure}}==
<lang lisp>(doseq [item collection] (println item))</lang>
<syntaxhighlight lang="lisp">(doseq [item collection] (println item))</syntaxhighlight>

=={{header|CLU}}==

As in Python (which no doubt got the idea from CLU), every <em>for</em> loop in
CLU is really a <em>foreach</em>, and iterating over a range of numbers is done
by using an iterator (e.g. <code>int$from_to</code>).

Unlike Python, the <em>for</em> loop '''only''' accepts iterators, and collections
are not automatically cast into iterators. To loop over the elements of an array,
one needs to explicitly use the <code>elements</code> iterator.

<syntaxhighlight lang="clu">start_up = proc ()
po: stream := stream$primary_output()
words: array[string] := array[string]$
["enemy", "lasagna", "robust", "below", "wax"]
for word: string in array[string]$elements(words) do
stream$putl(po, word)
end
end start_up</syntaxhighlight>


=={{header|CMake}}==
=={{header|CMake}}==
<lang cmake>set(list one.c two.c three.c)
<syntaxhighlight lang="cmake">set(list one.c two.c three.c)


foreach(file ${list})
foreach(file ${list})
message(${file})
message(${file})
endforeach(file)</lang>
endforeach(file)</syntaxhighlight>

=={{header|COBOL}}==
The following is in the Managed COBOL dialect:
{{trans|C#}}
{{works with|Visual COBOL}}
<syntaxhighlight lang="cobol">01 things occurs 3.
...
set content of things to ("Apple", "Banana", "Coconut")
perform varying thing as string through things
display thing
end-perform</syntaxhighlight>

=={{header|ColdFusion}}==
<syntaxhighlight lang="cfm">
<Cfloop list="Fee, Fi, Foe, Fum" index="i">
<Cfoutput>#i#!</Cfoutput>
</Cfloop>
</syntaxhighlight>


=={{header|Common Lisp}}==
=={{header|Common Lisp}}==
<lang lisp>(loop for i in list do (print i))</lang>
<syntaxhighlight lang="lisp">(loop for i in list do (print i))</syntaxhighlight>
or
<syntaxhighlight lang="lisp">(map nil #'print list)</syntaxhighlight>
or
or
<lang lisp>(map nil #'print list)</lang>
<syntaxhighlight lang="lisp">(dolist (x the-list) (print x))</syntaxhighlight>
or
=={{header|Creative Basic}}==
<syntaxhighlight lang="lisp">(use-package :iterate)
<lang Creative Basic>
(iter
DEF AnArray[11]:INT
(for x in the-list)
(print x))</syntaxhighlight>


=== Using DO ===
AnArray=0,1,2,3,4,5,6,7,8,9,10
<syntaxhighlight lang="lisp">
(let ((the-list '(1 7 "foo" 1 4))) ; Set the-list as the list
(do ((i the-list (rest i))) ; Initialize to the-list and set to rest on every loop
((null i)) ; Break condition
(print (first i)))) ; On every loop print list's first element
</syntaxhighlight>


{{out}}
'A console only program will work without OPENCONSOLE and
<pre>
'CLOSECONSOLE; however, it does not hurt to use them.
1
OPENCONSOLE
7

"foo"
FOR X=0 TO 10
1
4
PRINT AnArray[X]
</pre>

NEXT X

'keep the console from closing right away.
DO:UNTIL INKEY$<>""

CLOSECONSOLE

'because this is a console only program.
END
</lang>


=={{header|D}}==
=={{header|D}}==
This works if ''collection'' is a string/array/associative array, or if implements an appropriate ''opApply'' function, or if it has the basic Range methods.
This works if ''collection'' is a string/array/associative array, or if implements an appropriate ''opApply'' function, or if it has the basic Range methods.
<lang d>import std.stdio: writeln;
<syntaxhighlight lang="d">import std.stdio: writeln;


void main() {
void main() {
Line 474: Line 1,080:
foreach (key, value; collection3)
foreach (key, value; collection3)
writeln(key, " ", value);
writeln(key, " ", value);
}</lang>
}</syntaxhighlight>
{{out}}
{{out}}
<pre>A
<pre>A
Line 490: Line 1,096:


=={{header|Dao}}==
=={{header|Dao}}==
<lang dao>items = { 1, 2, 3 }
<syntaxhighlight lang="dao">items = { 1, 2, 3 }
for( item in items ) io.writeln( item )</lang>
for( item in items ) io.writeln( item )</syntaxhighlight>


=={{header|Delphi}}==
=={{header|Delphi}}==
Line 497: Line 1,103:


Supports arrays (single, multidimensional, and dynamic), sets, strings, collections and any class or interface that implements GetEnumerator().
Supports arrays (single, multidimensional, and dynamic), sets, strings, collections and any class or interface that implements GetEnumerator().
<lang Delphi>program LoopForEach;
<syntaxhighlight lang="delphi">program LoopForEach;


{$APPTYPE CONSOLE}
{$APPTYPE CONSOLE}
Line 506: Line 1,112:
for s in 'Hello' do
for s in 'Hello' do
Writeln(s);
Writeln(s);
end.</lang>
end.</syntaxhighlight>
Output:
Output:
<pre>H
<pre>H
Line 513: Line 1,119:
l
l
o</pre>
o</pre>

=={{header|Dragon}}==
<syntaxhighlight lang="dragon">
for value : array {
showln value
}
</syntaxhighlight>

=={{header|Dyalect}}==
<syntaxhighlight lang="dyalect">for i in [1,2,3] {
print(i)
}</syntaxhighlight>

This code would work for any type that has a method "iter" (returning an iterator). In fact a runtime environment silently calls this method for you here and creates an iterator out of an array. The code above is absolutely identical to:

<syntaxhighlight lang="dyalect">for i in [1,2,3].Iterate() {
print(i)
}</syntaxhighlight>

This would perfectly work with any custom iterator as well:

<syntaxhighlight lang="dyalect">func myCollection() {
yield 1
yield 2
yield 3
}

for i in myCollection() {
print(i)
}</syntaxhighlight>

All three code samples would output:

<pre>1
2
3</pre>


=={{header|E}}==
=={{header|E}}==
<lang e>for e in theCollection {
<syntaxhighlight lang="e">for e in theCollection {
println(e)
println(e)
}</lang>
}</syntaxhighlight>
In E, the for ... in ... loop is also used for iterating over numeric ranges; see [[Loop/For#E]].
In E, the for ... in ... loop is also used for iterating over numeric ranges; see [[Loop/For#E]].

=={{header|EasyLang}}==
<syntaxhighlight lang="easylang">
for i in [ 5 1 19 25 12 1 14 7 ]
print i
.
</syntaxhighlight>

=={{header|EchoLisp}}==
<syntaxhighlight lang="scheme">
(define my-list '( albert simon antoinette))
(for ((h my-list)) (write h))
albert simon antoinette

(define my-vector #(55 66 soixante-dix-sept))
(for (( u my-vector)) (write u))
55 66 soixante-dix-sept

(define my-string "Longtemps")
(for ((une-lettre my-string)) (write une-lettre))
"L" "o" "n" "g" "t" "e" "m" "p" "s"

;; etc ... for other collections like Streams, Hashes, Graphs, ...
</syntaxhighlight>

=={{header|Ecstasy}}==
<syntaxhighlight lang="java">
module LoopForEach {
@Inject Console console;
void run() {
val vals = [10, 20, 30, 40];
console.print("Array of values:");
Loop: for (val val : vals) {
console.print($" value #{Loop.count + 1}: {val}");
}

Map<String, Int> pairs = ["x"=42, "y"=69];
console.print("\nKeys and values:");
for ((String key, Int val) : pairs) {
console.print($" {key}={val}");
}
console.print("\nJust the keys:");
Loop: for (String key : pairs) {
console.print($" key #{Loop.count + 1}: {key}");
}

console.print("\nValues from a range:");
for (Int n : 1..5) {
console.print($" {n}");
}
}
}
</syntaxhighlight>

{{out}}
<pre>
Array of values:
value #1: 10
value #2: 20
value #3: 30
value #4: 40

Keys and values:
x=42
y=69

Just the keys:
key #1: x
key #2: y

Values from a range:
1
2
3
4
5
</pre>

=={{header|Ed}}==

Print all (newline-separated) lines in the file.

<syntaxhighlight lang="sed">
,p
</syntaxhighlight>


=={{header|Efene}}==
=={{header|Efene}}==
Any data structure can be printed as a whole, preformated:
Any data structure can be printed as a whole, preformated:
<lang efene>io.format("~p~n", [Collection])</lang>
<syntaxhighlight lang="efene">io.format("~p~n", [Collection])</syntaxhighlight>
However, to iterate over each element of a list, Efene uses <tt>lists.map/2</tt>, except in the case of IO where <tt>lists.foreach/2</tt> has to be used as the evaluation order is defined to be the same as the order of the elements in the list.
However, to iterate over each element of a list, Efene uses <tt>lists.map/2</tt>, except in the case of IO where <tt>lists.foreach/2</tt> has to be used as the evaluation order is defined to be the same as the order of the elements in the list.
<lang efene>lists.foreach(fn (X) { io.format("~p~n", [X]) }, Collection)</lang>
<syntaxhighlight lang="efene">lists.foreach(fn (X) { io.format("~p~n", [X]) }, Collection)</syntaxhighlight>


=={{header|Eiffel}}==
=={{header|Eiffel}}==
{{works with|EiffelStudio|6.6 beta (with provisional loop syntax)}}
{{works with|EiffelStudio|6.6 beta (with provisional loop syntax)}}
The iteration (foreach) form of the Eiffel loop construct is introduced by the keyword <code lang="eiffel">across</code>.
The iteration (foreach) form of the Eiffel loop construct is introduced by the keyword <code lang="eiffel">across</code>.
<lang eiffel > across my_list as ic loop print (ic.item) end</lang>
<syntaxhighlight lang="eiffel "> across my_list as ic loop print (ic.item) end</syntaxhighlight>
The local entity <code lang="eiffel">ic</code> is an instance of the library class <code lang="eiffel">ITERATION_CURSOR</code>. The cursor's feature <code lang="eiffel">item</code> provides access to each structure element. Descendants of class <code lang="eiffel">ITERATION_CURSOR</code> can be created to handle specialized iteration algorithms. The types of objects that can be iterated across (<code lang="eiffel">my_list</code> in the example) are based on classes that inherit from the library class <code lang="eiffel">ITERABLE</code>
The local entity <code lang="eiffel">ic</code> is an instance of the library class <code lang="eiffel">ITERATION_CURSOR</code>. The cursor's feature <code lang="eiffel">item</code> provides access to each structure element. Descendants of class <code lang="eiffel">ITERATION_CURSOR</code> can be created to handle specialized iteration algorithms. The types of objects that can be iterated across (<code lang="eiffel">my_list</code> in the example) are based on classes that inherit from the library class <code lang="eiffel">ITERABLE</code>
===Boolean expression variant===
===Boolean expression variant===
Line 535: Line 1,262:


This iteration is a boolean expression which is true if all items in <code>my_list</code> have counts greater than three:
This iteration is a boolean expression which is true if all items in <code>my_list</code> have counts greater than three:
<lang eiffel> across my_list as ic all ic.item.count > 3 end</lang>
<syntaxhighlight lang="eiffel"> across my_list as ic all ic.item.count > 3 end</syntaxhighlight>
Whereas, the following is true if at least one item has a count greater than three:
Whereas, the following is true if at least one item has a count greater than three:
<lang eiffel> across my_list as ic some ic.item.count > 3 end</lang>
<syntaxhighlight lang="eiffel"> across my_list as ic some ic.item.count > 3 end</syntaxhighlight>


=={{header|Ela}}==
=={{header|Ela}}==
<syntaxhighlight lang="ela">open monad io
===Standard Approach===
<lang ela>open console imperative
each [] = do return ()
each (x::xs) = do
putStrLn $ show x
each xs</syntaxhighlight>


=={{header|Elena}}==
each writen [1..10]</lang>
ELENA 6.x :
Function 'each' is defined in imperative module as:
<syntaxhighlight lang="elena">import system'routines;
<lang ela>each f (x::xs) = f x $ each f xs
import extensions;
each _ [] = ()</lang>
This also can be accomplished using 'map':
public program()
<lang ela>open console list
{
var things := new string[]{"Apple", "Banana", "Coconut"};
things.forEach::(thing)
{
console.printLine(thing)
}
}</syntaxhighlight>


=== Using foreach statement template ===
_ = map writen [1..10]</lang>
<syntaxhighlight lang="elena">import extensions;
public program()
{
var things := new string[]{"Apple", "Banana", "Coconut"};
foreach(var thing; in things)
{
console.printLine(thing)
}
}</syntaxhighlight>


=={{header|Elixir}}==
===Alternate Approach===
<syntaxhighlight lang="elixir">iex(1)> list = [1,3.14,"abc",[3],{0,5}]
<lang ela>each (x::xs) = writen x $ each xs
[1, 3.14, "abc", [3], {0, 5}]
each [] = ()
iex(2)> Enum.each(list, fn x -> IO.inspect x end)
1
3.14
"abc"
[3]
{0, 5}
:ok</syntaxhighlight>


=={{header|Emacs Lisp}}==
each [1..10]</lang>
For a list either <code>dolist</code> macro

<syntaxhighlight lang="lisp">(dolist (x '(1 2 3 4))
(message "x=%d" x))</syntaxhighlight>

or <code>mapc</code> function

<syntaxhighlight lang="lisp">(mapc (lambda (x)
(message "x=%d" x))
'(1 2 3 4))</syntaxhighlight>

{{libheader|cl-lib}}

<syntaxhighlight lang="lisp">(cl-loop for x in '(1 2 3 4) do (message "x=%d" x))</syntaxhighlight>


=={{header|Erlang}}==
=={{header|Erlang}}==
Any data structure can be printed as a whole, preformated:
Any data structure can be printed as a whole, preformated:
<lang erlang>io:format("~p~n",[Collection]).</lang>
<syntaxhighlight lang="erlang">io:format("~p~n",[Collection]).</syntaxhighlight>
However, to iterate over each element of a list, Erlang uses <tt>lists:map/2</tt>, except in the case of IO where <tt>lists:foreach/2</tt> has to be used as the evaluation order is defined to be the same as the order of the elements in the list.
However, to iterate over each element of a list, Erlang uses <tt>lists:map/2</tt>, except in the case of IO where <tt>lists:foreach/2</tt> has to be used as the evaluation order is defined to be the same as the order of the elements in the list.
<lang erlang>lists:foreach(fun(X) -> io:format("~p~n",[X]) end, Collection).</lang>
<syntaxhighlight lang="erlang">lists:foreach(fun(X) -> io:format("~p~n",[X]) end, Collection).</syntaxhighlight>

=={{header|ERRE}}==
It's an extension of 'standard' FOR loop: constant list must be explicit.
<syntaxhighlight lang="erre">
FOR INDEX$=("The","quick","brown","fox","jumps","over","the","lazy","dog.") DO
PRINT(INDEX$;" ";)
END FOR
PRINT
</syntaxhighlight>

=={{header|Euphoria}}==
{{works with|OpenEuphoria}}
<syntaxhighlight lang="euphoria">
include std/console.e

sequence s = {-2,-1,0,1,2} --print elements of a numerical list
for i = 1 to length(s) do
? s[i]
end for

puts(1,'\n')

s = {"Name","Date","Field1","Field2"} -- print elements of a list of 'strings'
for i = 1 to length(s) do
printf(1,"%s\n",{s[i]})
end for

puts(1,'\n')

for i = 1 to length(s) do -- print subelements of elements of a list of 'strings'
for j = 1 to length(s[i]) do
printf(1,"%s\n",s[i][j])
end for
puts(1,'\n')
end for

if getc(0) then end if
</syntaxhighlight>
{{out}}
<pre>
-2
-1
0
1
2

Name
Date
Field1
Field2

N
a
m
e

D
a
t
e

F
i
e
l
d
1

F
i
e
l
d
2
</pre>

=={{header|F_Sharp|F#}}==
We can use ''for'' directly or list iteration.
<syntaxhighlight lang="fsharp">for i in [1 .. 10] do printfn "%d" i

List.iter (fun i -> printfn "%d" i) [1 .. 10]</syntaxhighlight>


=={{header|Factor}}==
=={{header|Factor}}==
<lang factor>{ 1 2 4 } [ . ] each</lang>
<syntaxhighlight lang="factor">{ 1 2 4 } [ . ] each</syntaxhighlight>


=={{header|Fantom}}==
=={{header|Fantom}}==
Use <code>each</code> method to iterate over a collection of items in a <code>List</code>.
Use <code>each</code> method to iterate over a collection of items in a <code>List</code>.
<lang fantom>class Main
<syntaxhighlight lang="fantom">class Main
{
{
public static Void main ()
public static Void main ()
Line 579: Line 1,431:
}
}
}
}
}</lang>
}</syntaxhighlight>


=={{header|friendly interactive shell}}==
=={{header|Fennel}}==
====sequential table====
Unlike, bash or csh, the PATH variable is automatically converted to real array.
<syntaxhighlight lang="fennel">(each [k v (ipairs [:apple :banana :orange])]
<lang fishshell>for path in $PATH
(print k v))</syntaxhighlight>
echo You have $path in PATH.
{{out}}
end</lang>
<pre>1 apple
2 banana
3 orange</pre>
====key-value table====
<syntaxhighlight lang="fennel">(each [k v (pairs {:apple :x :banana 4 :orange 3})]
(print k v))</syntaxhighlight>
{{out}}
<pre>apple x
banana 4
orange 3</pre>
=={{header|Forth}}==
<syntaxhighlight lang="forth">create a 3 , 2 , 1 ,
: .array ( a len -- )
cells bounds do i @ . cell +loop ; \ 3 2 1</syntaxhighlight>
===FOREACH===
The thing about extensible languages is if you need FOREACH, you can have FOREACH.
The Forth ' operator returns the "execution token" (XT) of a Forth word. An XT can be run with EXECUTE.
If we apply an appropriate XT to all the elements of an array we have it.


<syntaxhighlight lang="forth">: FOREACH ( array size XT --)
Sample output:
>R \ save execution token on return stack
<pre>
CELLS BOUNDS \ convert addr,len -> last,first addresses
You have /bin in PATH.
BEGIN
You have /usr/bin in PATH.
2DUP > \ test addresses
</pre>
WHILE ( last>first )
DUP R@ EXECUTE \ apply the execution token to the address
CELL+ \ move first to the next memory cell
REPEAT
R> DROP \ clean return stack
2DROP \ and data stack
;

\ Make an operator to fetch contents of an address and print
: ? ( addr --) @ . ;

CREATE A[] 9 , 8 , 7 , 6 , 5 , 4 , 3 , 2 , 1 , 0 ,

\ Usage example:
A[] 10 ' ? FOREACH </syntaxhighlight>


=={{header|Fortran}}==
=={{header|Fortran}}==
<lang fortran>program main
<syntaxhighlight lang="fortran">program main


implicit none
implicit none
Line 609: Line 1,494:
write(*,'(A)') colors
write(*,'(A)') colors


end program main</lang>
end program main</syntaxhighlight>


=={{header|Forth}}==
=={{header|friendly interactive shell}}==
Unlike, bash or csh, the PATH variable is automatically converted to real array.
<lang forth>create a 3 , 2 , 1 ,
<syntaxhighlight lang="fishshell">for path in $PATH
: .array ( a len -- )
echo You have $path in PATH.
cells bounds do i @ . cell +loop ; \ 3 2 1</lang>
end</syntaxhighlight>


Sample output:
=={{header|F_Sharp|F#}}==
<pre>
We can use ''for'' directly or list iteration.
You have /bin in PATH.
<lang fsharp>for i in [1 .. 10] do printfn "%d" i
You have /usr/bin in PATH.
</pre>

=={{header|Frink}}==
Frink's <CODE>for</CODE> loop is actually a "for each" loop which can iterate over built-in collection types including arrays, sets, dictionaries, enumerating expressions, and Java types such as Map, Iterator, Enumeration, etc.
<syntaxhighlight lang="frink">
array = [1, 2, 3, 5, 7]
for n = array
println[n]
</syntaxhighlight>

=={{header|FutureBasic}}==
<syntaxhighlight lang="futurebasic">

window 1

void local fn DoIt
CFArrayRef array = @[@"Alpha",@"Bravo",@"Charlie",@"Delta",@"Echo",@"FutureBasic"]
CFStringRef string
for string in array
print string
next
end fn

fn DoIt

HandleEvents
</syntaxhighlight>
{{out}}
<pre>
Alpha
Bravo
Charlie
Delta
Echo
FutureBasic
</pre>

=={{header|GAP}}==

<syntaxhighlight lang="gap">for p in AlternatingGroup(4) do
Print(p, "\n");
od;


()
List.iter (fun i -> printfn "%d" i) [1 .. 10]</lang>
(1,3,2)
(1,2,3)
(1,4,3)
(2,4,3)
(1,3)(2,4)
(1,2,4)
(1,4)(2,3)
(2,3,4)
(1,3,4)
(1,2)(3,4)
(1,4,2)</syntaxhighlight>


=={{header|Go}}==
=={{header|Go}}==
<code>range</code> works with all of the built-in container-types. With one variable (''i''), it gives you the key/index of every item. With two variables (''i'', ''x''), it gives you both the key/index and value/item. For channels, only the single-variable variant is allowed.
<code>range</code> works with all of the built-in container-types. With one variable (''i''), it gives you the key/index of every item. With two variables (''i'', ''x''), it gives you both the key/index and value/item. For channels, only the single-variable variant is allowed.
<lang go>func printAll(values []int) {
<syntaxhighlight lang="go">func printAll(values []int) {
for i, x := range values {
for i, x := range values {
fmt.Printf("Item %d = %d\n", i, x)
fmt.Printf("Item %d = %d\n", i, x)
}
}
}</lang>
}</syntaxhighlight>


=={{header|Groovy}}==
=={{header|Groovy}}==
"for" loop:
"for" loop:
<lang groovy>def beatles = ["John", "Paul", "George", "Ringo"]
<syntaxhighlight lang="groovy">def beatles = ["John", "Paul", "George", "Ringo"]


for(name in beatles) {
for(name in beatles) {
println name
println name
}</lang>
}</syntaxhighlight>
"each()" method:<br>
"each()" method:<br>
Though technically not a loop, most Groovy programmers would use the somewhat more terse "each()" method on the list itself in preference to the "for" loop construct.
Though technically not a loop, most Groovy programmers would use the somewhat more terse "each()" method on the list itself in preference to the "for" loop construct.
<lang groovy>beatles.each {
<syntaxhighlight lang="groovy">beatles.each {
println it
println it
}</lang>
}</syntaxhighlight>
Output (same for either):
Output (same for either):
<pre>John
<pre>John
Line 647: Line 1,588:
George
George
Ringo</pre>
Ringo</pre>

=={{header|Halon}}==
<syntaxhighlight lang="halon">$things = ["Apple", "Banana", "Coconut"];

foreach ($things as $thing) {
echo $thing;
}</syntaxhighlight>


=={{header|Haskell}}==
=={{header|Haskell}}==
<lang haskell>import Control.Monad (forM_)
<syntaxhighlight lang="haskell">import Control.Monad (forM_)
forM_ collect print</lang>
forM_ collect print</syntaxhighlight>
which is the same as
which is the same as
<lang haskell>mapM_ print collect</lang>
<syntaxhighlight lang="haskell">mapM_ print collect</syntaxhighlight>


=={{header|Haxe}}==
=={{header|Haxe}}==
<syntaxhighlight lang="haxe">var a = [1, 2, 3, 4];
<lang haxe>for(i in 1...10) Sys.println(i);</lang>

for (i in a)
Sys.println(i);</syntaxhighlight>


=={{header|HicEst}}==
=={{header|HicEst}}==
<lang hicest>CHARACTER days="Monday Tuesday Wednesday Thursday Friday Saturday Sunday "
<syntaxhighlight lang="hicest">CHARACTER days="Monday Tuesday Wednesday Thursday Friday Saturday Sunday "


items = INDEX(days, ' ', 256) ! 256 = count option
items = INDEX(days, ' ', 256) ! 256 = count option
Line 664: Line 1,615:
EDIT(Text=days, ITeM=j, Parse=today)
EDIT(Text=days, ITeM=j, Parse=today)
WRITE() today
WRITE() today
ENDDO</lang>
ENDDO</syntaxhighlight>


=={{header|Io}}==
=={{header|Hy}}==
<lang io>collection foreach(println)</lang>
<syntaxhighlight lang="clojure">(for [x collection] (print x))</syntaxhighlight>


=={{header|Icon}} and {{header|Unicon}}==
=={{header|Icon}} and {{header|Unicon}}==
The example below X can be a list, string, table or other data type.
The example below X can be a list, string, table or other data type.
<lang Icon>procedure main()
<syntaxhighlight lang="icon">procedure main()
X := [1,2,3,-5,6,9]
X := [1,2,3,-5,6,9]
every x := !L do
every x := !L do
write(x)
write(x)
end</lang>
end</syntaxhighlight>
This loop can be written somewhat more concisely as:
This loop can be written somewhat more concisely as:
<lang Icon>every write(!L)</lang>
<syntaxhighlight lang="icon">every write(!L)</syntaxhighlight>
=={{header|IWBASIC}}==
<lang IWBASIC>
== Linked List ==


=={{header|Io}}==
DEF AList:POINTER
<syntaxhighlight lang="io">collection foreach(println)</syntaxhighlight>


=={{header|J}}==
DEF X:INT
<syntaxhighlight lang="j"> echo every i.10
0
1
2
3
4
5
6
7
8
9</syntaxhighlight>


That said, J's <code>for.</code> provides a "foreach" mechanism.
AList=ListCreate()


<syntaxhighlight lang="J"> {{for_i. i. y do. echo i end.}}10
'add items to the list
0
FOR X=0 TO 10
1
POINTER Temp=ListAdd(AList,NEW(INT,1))
2
#<INT>temp=X
3
'The hash ("#") dereferencing operator is unique to IWBASIC and Creative Basic, and
4
'it is suitable for most basic pointer needs. IWBASIC also supports a "C style"
5
'dereferencing operator: "*". And that will work here too.
6
NEXT X
7

8
'A program compiled as console only does not need 'the commands to open and
9
'close the console. However, it does not hurt to use them.
</syntaxhighlight>
OPENCONSOLE

'***Iterate the list with the "for each" loop***
FOR Temp=EACH AList AS INT

PRINT #Temp
NEXT

PRINT

'A press any key to continue message is automatic in a program compiled as a console only
program. I presume the compiler inserts the code.
CLOSECONSOLE

'Because this is a console only program.
END

== An Array ==

DEF AnArray[11]:INT

AnArray=0,1,2,3,4,5,6,7,8,9,10

OPENCONSOLE

FOR X=0 TO 10

PRINT AnArray[X]

NEXT X

PRINT

'a press any key message is automatic when compiled as console only.
CLOSECONSOLE

'Because this is a console only program.
END
</lang>

=={{header|J}}==
<lang J>smoutput each i.10</lang>


=={{header|Java}}==
=={{header|Java}}==
{{works with|Java|1.5+}}
{{works with|Java|1.5+}}
<lang java>Iterable<Type> collect;
<syntaxhighlight lang="java">Iterable<Type> collect;
...
...
for(Type i:collect){
for(Type i:collect){
System.out.println(i);
System.out.println(i);
}</lang>
}</syntaxhighlight>
This works for any array type as well as any type that implements the Iterable interface (including all Collections).
This works for any array type as well as any type that implements the Iterable interface (including all Collections).

{{works with|Java|1.8+}}
<syntaxhighlight lang="java">
Iterable collect;
...
collect.forEach(o -> System.out.println(o));
</syntaxhighlight>
This works with any Iterable, but not with arrays.


=={{header|JavaScript}}==
=={{header|JavaScript}}==
For arrays in ES5, we can use '''Array.forEach()''':
This works for any object, as well as arrays. It iterates over the keys of an object.
<syntaxhighlight lang="javascript">"alpha beta gamma delta".split(" ").forEach(function (x) {
<lang JavaScript>for (var a in o) {
console.log(x);
});</syntaxhighlight>
though it will probably be more natural – dispensing with side-effects, and allowing for easier composition of nested functions – to simply use '''Array.map()''',
<syntaxhighlight lang="javascript">console.log("alpha beta gamma delta".split(" ").map(function (x) {
return x.toUpperCase(x);
}).join("\n"));</syntaxhighlight>
or, more flexibly, and with greater generality, obtain an accumulating fold from '''Array.reduce()'''
<syntaxhighlight lang="javascript">console.log("alpha beta gamma delta".split(" ").reduce(function (a, x, i, lst) {
return lst.length - i + ". " + x + "\n" + a;
}, ""));</syntaxhighlight>
More generally, the following works for any object, including an array. It iterates over the keys of an object.
<syntaxhighlight lang="javascript">for (var a in o) {
print(o[a]);
print(o[a]);
}</lang>
}</syntaxhighlight>
However, it has the often unwanted feature that it lists inherited properties and methods of objects as well as the ones directly set on the object -- consider whether to filter out such properties inside the loop, for example:
However, it has the often unwanted feature that it lists inherited properties and methods of objects as well as the ones directly set on the object -- consider whether to filter out such properties inside the loop, for example:
<lang JavaScript>for (var a in o) {
<syntaxhighlight lang="javascript">for (var a in o) {
if (o.hasOwnProperty(a)) {
if (o.hasOwnProperty(a)) {
print(o[a]);
print(o[a]);
}
}
}</lang>
}</syntaxhighlight>

{{works with|JavaScript|1.6}}
{{works with|JavaScript|1.6}}
;Deprecated
;Deprecated
There is also a <tt>[https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Statements/for_each...in for each in]</tt> construct that iterates over the values of an object:
There is also a <tt>[https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Statements/for_each...in for each in]</tt> construct that iterates over the values of an object:
<lang JavaScript>h = {"one":1, "two":2, "three":3}
<syntaxhighlight lang="javascript">h = {"one":1, "two":2, "three":3}
for (x in h) print(x);
for (x in h) print(x);
for each (y in h) print(y);</syntaxhighlight>
/*
two
one
three
*/

for each (y in h) print(y);
/*
2
1
3
*/</lang>

{{works with|ECMAScript|6th edition}}
{{works with|ECMAScript|6th edition}}
There is also a <tt>[https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Statements/for...of for of]</tt> construct that iterates over the values of an object:
There is also a <tt>[https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Statements/for...of for of]</tt> construct that iterates over the values of an object:
<lang JavaScript>h = {"one":1, "two":2, "three":3}
<syntaxhighlight lang="javascript">h = {"one":1, "two":2, "three":3}
for (x in h) print(x);
for (x in h) print(x);
for (y of h) print(y);</syntaxhighlight>
/*
two
one
three
*/


=={{header|jq}}==
for (y of h) print(y);
'''Iterables''':
/*

2
In this section, the array defined by "example" is used as an example:
1
<syntaxhighlight lang="jq">def example: [1,2];</syntaxhighlight>
3
jq has two types of iterables -- JSON arrays and JSON objects. In both cases, the ".[]" filter may be used to iterate through the values, it being understand that for objects, the "values" are the values associated with the keys:
*/</lang>
<syntaxhighlight lang="jq">example | .[]
# or equivalently: example[]</syntaxhighlight>
<syntaxhighlight lang="jq">{"a":1, "b":2} | .[]
# or equivalently: {"a":1, "b":2}[]</syntaxhighlight>

In both cases, the output is the stream consisting of the values 1 followed by 2.

Sometimes it is necessary to use an alternative to ".[]". For example, one might want to generate an index along with the array elements. In such cases, the "range(m;n)" generator, which performs a similar role to C's "for(i=m; i<n; i++)", can be used for array. Here is how range/2 would be used to perform the task for an array:
<syntaxhighlight lang="jq">example | . as $a | range(0; length) | $a[.]</syntaxhighlight>
For JSON objects, the corresponding technique involves using <tt>keys</tt>, e.g.
<syntaxhighlight lang="jq">
{"a":1, "b":2} | . as $o | keys | map( [., $o[.]] )
</syntaxhighlight>
produces:
[["a",1],["b",2]]


'''Strings''':

To convert the constituent characters (or technically, codepoints) of a string into a stream of values, there are two techniques illustrated by these examples:
<syntaxhighlight lang="jq">"abc" | . as $s | range(0;length) | $s[.:.+1]

"abc" | explode | map( [.]|implode) | .[]</syntaxhighlight>

In both cases, the result is the stream of values: "a", "b", "c".

=={{header|Jsish}}==
Jsi supports ''for of'' for looping over element of an array.
<syntaxhighlight lang="javascript">for (str of "alpha beta gamma delta".split(' ')) { puts(str); }</syntaxhighlight>

{{out}}
<pre>alpha
beta
gamma
delta</pre>

=={{header|Julia}}==
{{trans|Python}}
<syntaxhighlight lang="julia">for i in collection
println(i)
end</syntaxhighlight>
The Julia <code>for</code> statement is always a "foreach", and the built-in <code>start:end</code> or <code>start:step:end</code> "range" syntax can be used for iteration over arithmetic sequences. Many Julia objects support iteration: arrays and tuples iterate over each item, strings iterate over each character, dictionaries iterate over (key,value) pairs, numeric scalars provide a length-1 iteration over their value, and so on.


=={{header|K}}==
=={{header|K}}==
<lang K> {`0:$x} ' !10</lang>
<syntaxhighlight lang="k"> {`0:$x} ' !10</syntaxhighlight>
<lang K> _sin ' (1; 2; 3;)</lang>
<syntaxhighlight lang="k"> _sin ' (1; 2; 3;)</syntaxhighlight>

=={{header|Klingphix}}==
<syntaxhighlight lang="klingphix">include ..\Utilitys.tlhy

( -2 "field" 3.14159 ( "this" "that" ) ) len [get ?] for

" " input</syntaxhighlight>
{{out}}
<pre>-2
field
3.14159
("this", "that")</pre>

=={{header|Kotlin}}==
<syntaxhighlight lang="scala">// version 1.0.6

fun main(args: Array<String>) {
val greek = arrayOf("alpha", "beta", "gamma", "delta")
for (letter in greek) print("$letter ")
println()
// or alternatively
greek.forEach { print("$it ") }
println()
}</syntaxhighlight>

{{out}}
<pre>
alpha beta gamma delta
alpha beta gamma delta
</pre>


=={{header|LabVIEW}}==
=={{header|LabVIEW}}==
[[LabVIEW]] has a feature known as an Auto-Indexed Tunnel. It is the very small orange box on the lower left of the for loop.<br/>{{VI solution|LabVIEW_Loops_Foreach.png}}
[[LabVIEW]] has a feature known as an Auto-Indexed Tunnel. It is the very small orange box on the lower left of the for loop.<br/>{{VI solution|LabVIEW_Loops_Foreach.png}}

=={{header|Lambdatalk}}==
<syntaxhighlight lang="scheme">
{def collection alpha beta gamma delta}
-> collection

{S.map {lambda {:i} {br}:i} {collection}}
->
alpha
beta
gamma
delta

or

{def S.foreach
{lambda {:s}
{if {S.empty? {S.rest :s}}
then {S.first :s}
else {S.first :s} {br}{S.foreach {S.rest :s}}}}}

{S.foreach {collection}}
->
alpha
beta
gamma
delta

</syntaxhighlight>

=={{header|Lang}}==
<syntaxhighlight lang="lang">
$collection = fn.arrayOf(1, 2, 3)

# Foreach loop [Works with iterable types (text, collections [array, list])]
$ele
foreach($[ele], $collection) {
fn.println($ele)
}

# Foreach function
# Array: fn.arrayForEach(&arr, func)
# List: fn.listForEach(&list, func)

fn.arrayForEach($collection, fn.println)
</syntaxhighlight>


=={{header|Lang5}}==
=={{header|Lang5}}==
<lang lang5>: >>say.(*) . ;
<syntaxhighlight lang="lang5">: >>say.(*) . ;
5 iota >>say.</lang>
5 iota >>say.</syntaxhighlight>


=={{header|Liberty BASIC}}==
=={{header|langur}}==
A for in loop iterates over values and a for of loop iterates over keys.
The most natural way is to use a csv list with a sentinel value.
<syntaxhighlight lang="langur">
<lang lb>in$ ="Not,Hardly,Just,Adequately,Quite,Really,Very,Fantastically,xyzzy"
for i in [1, 2, 3] {
element$ =""
writeln i
i =1 ' used to point to successive elements
}


val abc = "abc"
do
element$ =word$( in$, i, ",")
if element$ ="xyzzy" then exit do
print element$; " good!"
i =i +1
loop until 1 =2


for i in abc {
end</lang>
writeln i
Not good!
}
Hardly good!

Just good!
for i of abc {
Adequately good!
writeln abc[i]
Quite good!
}
Really good!

Very good!
for i in abc {
Fantastically good!
writeln cp2s(i)
}
</syntaxhighlight>

{{out}}
<pre>1
2
3
97
98
99
97
98
99
a
b
c</pre>

=={{header|Lasso}}==
<syntaxhighlight lang="lasso">array(1,2,3) => foreach { stdoutnl(#1) }</syntaxhighlight>
<syntaxhighlight lang="lasso">with i in array(1,2,3) do { stdoutnl(#i) }</syntaxhighlight>

=={{header|LDPL}}==
<syntaxhighlight lang="ldpl">data:
fruits is text list
fruit is text

procedure:
split "apple banana orange" by " " in fruits
for each fruit in fruits do
display fruit lf
repeat
</syntaxhighlight>
{{out}}
<pre>
apple
banana
orange
</pre>

=={{header|LFE}}==

<syntaxhighlight lang="lisp">(lists:foreach
(lambda (x)
(io:format "item: ~p~n" (list x)))
(lists:seq 1 10))
</syntaxhighlight>

=={{header|LIL}}==
<syntaxhighlight lang="tcl"># Loops/Foreach, in LIL
set collection [list 1 2 "three"]
append collection [list 4 5 six] # appended as a single item in collection
print "Collection is: $collection"

# using default "i" variable name set for each item
foreach $collection {print $i}

# user named variable in the steps, retrieving accumulated result of loop
# each loop step quotes two copies of the item
set newlist [foreach j $collection {quote $j $j}]
print "Result of second foreach: $newlist"</syntaxhighlight>

{{out}}
<pre>prompt$ lil loopsForeach.lil
Collection is: 1 2 three {4 5 six}
1
2
three
4 5 six
Result of second foreach: {1 1} {2 2} {three three} {4 5 six 4 5 six}</pre>

=={{header|Lingo}}==

<syntaxhighlight lang="lingo">days = ["monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday"]
repeat with day in days
put day
end repeat</syntaxhighlight>
A callback-based forEach() can be implemented like this:
<syntaxhighlight lang="lingo">----------------------------------------
-- One of the five native iterative methods defined in ECMAScript 5
-- @param {list} tList
-- @param {symbol} cbFunc
-- @param {object} [cbObj=_movie]
----------------------------------------
on forEach (tList, cbFunc, cbObj)
if voidP(cbObj) then cbObj = _movie
cnt = tList.count
repeat with i = 1 to cnt
call(cbFunc, cbObj, tList[i], i, tList)
end repeat
end</syntaxhighlight>
<syntaxhighlight lang="lingo">days = ["monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday"]
forEach(days, #alert, _player)</syntaxhighlight>


=={{header|Lisaac}}==
=={{header|Lisaac}}==
<lang Lisaac>"Lisaac loop foreach".split.foreach { word : STRING;
<syntaxhighlight lang="lisaac">"Lisaac loop foreach".split.foreach { word : STRING;
word.print;
word.print;
'\n'.print;
'\n'.print;
};</lang>
};</syntaxhighlight>

=={{header|LiveCode}}==
Livecode's ''for each'' operates on chunks which may be words, items, lines, tokens. Example is for items.<syntaxhighlight lang="livecode">repeat for each item x in "red, green, blue"
put x & cr
--wait 100 millisec -- req'd if you want to see in the LC Message Box (akin to repl)
end repeat</syntaxhighlight>


=={{header|Logo}}==
=={{header|Logo}}==
<lang logo>foreach [red green blue] [print ?]</lang>
<syntaxhighlight lang="logo">foreach [red green blue] [print ?]</syntaxhighlight>


=={{header|Lua}}==
=={{header|Lua}}==
Line 846: Line 1,980:


<code>pairs()</code> iterates over all entries in a table, but in no particular order:
<code>pairs()</code> iterates over all entries in a table, but in no particular order:
<lang lua>t={monday=1, tuesday=2, wednesday=3, thursday=4, friday=5, saturday=6, sunday=0, [7]="fooday"}
<syntaxhighlight lang="lua">t={monday=1, tuesday=2, wednesday=3, thursday=4, friday=5, saturday=6, sunday=0, [7]="fooday"}
for key, value in pairs(t) do
for key, value in pairs(t) do
print(value, key)
print(value, key)
end</lang>
end</syntaxhighlight>
Output:
Output:
<pre>
<pre>
Line 863: Line 1,997:
<code>ipairs()</code> iterates over table entries with positive integer keys,
<code>ipairs()</code> iterates over table entries with positive integer keys,
and is used to iterate over lists in order.
and is used to iterate over lists in order.
<lang lua>l={'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday', not_a_number='fooday', [0]='today', [-1]='yesterday' }
<syntaxhighlight lang="lua">l={'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday', not_a_number='fooday', [0]='today', [-1]='yesterday' }
for key, value in ipairs(l) do
for key, value in ipairs(l) do
print(key, value)
print(key, value)
end</lang>
end</syntaxhighlight>
Output:
Output:
<pre>
<pre>
Line 879: Line 2,013:
Note that <code>ipairs()</code> ignores non-numeric and non-positive integer keys.
Note that <code>ipairs()</code> ignores non-numeric and non-positive integer keys.


=={{header|Mathematica}}==
=={{header|M2000 Interpreter}}==
Iterators we have for Arrays, Inventories and Stacks (containers). Each(object Start to End), or Each(object 1 to -1) or Each(Object, 1,-1). We can use -2 for second from end item. We can use step inside while iterator {} using Iterator=Each(object, new_start, end_item). We can read cursor using ^. So Print k^, k2^, k1^ return positions (from 0 for inventories). We can use more than one iterators for an object.

<syntaxhighlight lang="m2000 interpreter">
Module Checkit {
\\ Inventories may have keys or keys/values
\\ here keys are values too
Inventory Alfa="Apple", "Banana", "Coconut"
\\ key 30 has value 25, other keys have value same as key.
Inventory Beta=100, 30:=25, 20, 5
Print "Parallel"
k=Each(Alfa)
k1=Each(Alfa End to Start)
k2=Each(Beta)
\\ Parallel iterators
\\ when one of them end then while end too.
\\ so 5 not printed. Print 100, 25, 20
While k,k2, k1 {
Print Eval$(k), Eval$(k1), Eval(k2)
}
Print "Nested"
\\ Nested iterators
k=Each(Alfa)
While k {
k1=Each(Alfa End to Start)
While k1 {
Print Eval$(k), Eval$(k1)
}
}
}
Checkit
</syntaxhighlight>

=={{header|Maple}}==
<syntaxhighlight lang="maple">
for p in [2, 3, 5, 7] do
print(p);
end do;
</syntaxhighlight>

=={{header|Mathematica}}/{{header|Wolfram Language}}==
Foreach over list of strings
Foreach over list of strings
<lang mathematica>s = (StringSplit@Import["ExampleData/USConstitution.txt"])[[1;;7]];
<syntaxhighlight lang="mathematica">s = (StringSplit@Import["ExampleData/USConstitution.txt"])[[1;;7]];
Do[
Do[
Print@i,
Print@i,
{i, s}
{i, s}
]</lang>
]</syntaxhighlight>
Output:
Output:
<pre>We
<pre>We
Line 896: Line 2,070:


=={{header|MATLAB}} / {{header|Octave}}==
=={{header|MATLAB}} / {{header|Octave}}==
<lang Matlab> list1 = [1,5,6,7,-7,-9];
<syntaxhighlight lang="matlab"> list1 = [1,5,6,7,-7,-9];
for k = list1, % list1 must be a row vector (i.e. array of size 1xn)
for k = list1, % list1 must be a row vector (i.e. array of size 1xn)
printf('%i\n',k)
printf('%i\n',k)
end; </lang>
end; </syntaxhighlight>
<lang Matlab> list2 = {'AA','BB','CC'};
<syntaxhighlight lang="matlab"> list2 = {'AA','BB','CC'};
for k = list2, % list2 must be a row vector (i.e. array of size 1xn)
for k = list2, % list2 must be a row vector (i.e. array of size 1xn)
printf('%s\n',k{1})
printf('%s\n',k{1})
end; </lang>
end; </syntaxhighlight>
A vectorized version of the code is
A vectorized version of the code is
<lang Matlab> printf('%d\n',list1);
<syntaxhighlight lang="matlab"> printf('%d\n',list1);
printf('%s\n',list2{:}); </lang>
printf('%s\n',list2{:}); </syntaxhighlight>


=={{header|Maxima}}==
=={{header|Maxima}}==
<lang maxima>for n in [2, 3, 5, 7] do print(n);</lang>
<syntaxhighlight lang="maxima">for n in [2, 3, 5, 7] do print(n);</syntaxhighlight>


=={{header|MAXScript}}==
=={{header|MAXScript}}==
<lang maxscript>for i in collect do
<syntaxhighlight lang="maxscript">
arr = for i in 1 to 50 collect ("Number: " + (random 10 99) as string)
(
makeuniquearray arr
print i
sort arr
)</lang>

for i in arr do print i as string
</syntaxhighlight>


=={{header|Metafont}}==
=={{header|Metafont}}==
If we have a list of arbitrary items, we can simply use for:
If we have a list of arbitrary items, we can simply use for:
<lang metafont>for x = "mary", "had", "a", "little", "lamb": message x; endfor
<syntaxhighlight lang="metafont">for x = "mary", "had", "a", "little", "lamb": message x; endfor
end</lang>
end</syntaxhighlight>
The list can be generated in place by any suitable macro or another loop... e.g. let us suppose we have things like <tt>a[n]</tt> defined (with maximum n being 10). Then
The list can be generated in place by any suitable macro or another loop... e.g. let us suppose we have things like <tt>a[n]</tt> defined (with maximum n being 10). Then
<lang metafont>for x = for i = 1 upto 9: a[i], endfor, a[10]: show x; endfor
<syntaxhighlight lang="metafont">for x = for i = 1 upto 9: a[i], endfor, a[10]: show x; endfor
end</lang>
end</syntaxhighlight>
works more like a <tt>foreach</tt>; we could make a macro to hide the strangeness of such a code.
works more like a <tt>foreach</tt>; we could make a macro to hide the strangeness of such a code.

=={{header|min}}==
{{works with|min|0.19.3}}
<syntaxhighlight lang="min">(1 2 3) 'puts foreach</syntaxhighlight>

=={{header|MiniScript}}==

<syntaxhighlight lang="miniscript">for i in collection
print i
end</syntaxhighlight>
The MiniScript <code>for</code> statement is always a "foreach", and the standard <code>range</code> intrinsic can be used for iteration over arithmetic sequences. All MiniScript collection types support iteration: lists iterate over each item, strings iterate over each character, and maps/objects iterate over (key,value) pairs.


=={{header|MOO}}==
=={{header|MOO}}==
<lang moo>things = {"Apple", "Banana", "Coconut"};
<syntaxhighlight lang="moo">things = {"Apple", "Banana", "Coconut"};
for thing in (things)
for thing in (things)
player:tell(thing);
player:tell(thing);
endfor</lang>
endfor</syntaxhighlight>

=={{header|Nanoquery}}==
Like Python, Nanoquery supports for...in syntax for list types and strings.
<syntaxhighlight lang="nanoquery">for item in collection
println item
end</syntaxhighlight>
<strong>Some examples:</strong>
<syntaxhighlight lang="nanoquery">for n in {1,3,5,7,9}
print n + " "
end
println

for char in "test string"
print char
end
println</syntaxhighlight>
{{out}}
<pre>1 3 5 7 9
test string</pre>


=={{header|Nemerle}}==
=={{header|Nemerle}}==
This works on anything which implements the IEnumerable interface.
This works on anything which implements the IEnumerable interface.
<lang Nemerle>def things = ["Apple", "Banana", "Coconut"];
<syntaxhighlight lang="nemerle">def things = ["Apple", "Banana", "Coconut"];


foreach (thing in things) WriteLine(thing.ToLower());
foreach (thing in things) WriteLine(thing.ToLower());
foreach (i in [5, 10 .. 100]) Write($"$i\t");</lang>
foreach (i in [5, 10 .. 100]) Write($"$i\t");</syntaxhighlight>


=={{header|NetRexx}}==
=={{header|NetRexx}}==
<lang NetRexx>/* NetRexx */
<syntaxhighlight lang="netrexx">/* NetRexx */
options replace format comments java crossref savelog symbols nobinary
options replace format comments java crossref savelog symbols nobinary


Line 953: Line 2,160:
loop while daysi.hasNext
loop while daysi.hasNext
say daysi.next
say daysi.next
end</lang>
end</syntaxhighlight>


=={{header|Nimrod}}==
=={{header|NewLISP}}==
<syntaxhighlight lang="newlisp">(map println '(Apple Banana Coconut))</syntaxhighlight>
<lang nimrod>var list: seq[string] = @[]

list.add("lorem")
=={{header|Nim}}==
list.add("ipsum")
<syntaxhighlight lang="nim">let list = ["lorem", "ipsum", "dolor"]
list.add("dolor")
for i in items(list):
for item in list:
echo(i)</lang>
echo item</syntaxhighlight>
{{out}}
Output:
<pre>
<pre>lorem
lorem
ipsum
ipsum
dolor
dolor</pre>
=={{header|Nu}}==
<syntaxhighlight lang="nu">
let l = [a b c d]
for x in $l {print $x}
</syntaxhighlight>
{{out}}
<pre>
a
b
c
d
</pre>
</pre>

=={{header|Objeck}}==
<syntaxhighlight lang="objeck">fruits := ["Apple", "Banana", "Coconut"];
each(i : fruits) {
fruits[i]->PrintLine();
};</syntaxhighlight>


=={{header|Objective-C}}==
=={{header|Objective-C}}==
Line 973: Line 2,196:
{{works with|GNUstep}}
{{works with|GNUstep}}
{{works with|Cocoa}}
{{works with|Cocoa}}
<lang objc>NSArray *collect;
<syntaxhighlight lang="objc">NSArray *collect;
//...
// ...
for(Type i in collect){
for (Type i in collect) {
NSLog(@"%@", i);
NSLog(@"%@", i);
}</lang>
}</syntaxhighlight>
''collect'' can be any object that adopts the NSFastEnumeration protocol.
''collect'' can be any object that adopts the NSFastEnumeration protocol.


Or (always using OpenStep compatible frameworks):
Or (always using OpenStep compatible frameworks):
{{works with|Objective-C|<2.0}}
{{works with|Objective-C|<2.0}}
<lang objc>NSArray *collect;
<syntaxhighlight lang="objc">NSArray *collect;
//...
// ...
NSEnumerator *enm = [collect objectEnumerator];
NSEnumerator *enm = [collect objectEnumerator];
id i;
id i;
while( (i = [enm nextObject]) ) {
while ((i = [enm nextObject])) {
// do something with object i
// do something with object i
}</lang>
}</syntaxhighlight>

=={{header|Objeck}}==
<lang objeck>fruits := ["Apple", "Banana", "Coconut"];
each(i : fruits) {
fruits[i]->PrintLine();
};</lang>


=={{header|OCaml}}==
=={{header|OCaml}}==
List of integers:
List of integers:
<lang ocaml>List.iter
<syntaxhighlight lang="ocaml">List.iter
(fun i -> Printf.printf "%d\n" i)
(fun i -> Printf.printf "%d\n" i)
collect_list</lang>
collect_list</syntaxhighlight>
Array of integers:
Array of integers:
<lang ocaml>Array.iter
<syntaxhighlight lang="ocaml">Array.iter
(fun i -> Printf.printf "%d\n" i)
(fun i -> Printf.printf "%d\n" i)
collect_array</lang>
collect_array</syntaxhighlight>


=={{header|Octave}}==
=={{header|Octave}}==
<lang octave>a = [ 1,4,3,2 ];
<syntaxhighlight lang="octave">a = [ 1,4,3,2 ];
b = [ 1,2,3,4; 5,6,7,8 ];
b = [ 1,2,3,4; 5,6,7,8 ];
for v = a
for v = a
Line 1,014: Line 2,231:
for v = b
for v = b
disp(v); % v is the column vector [1;5], then [2;6] ...
disp(v); % v is the column vector [1;5], then [2;6] ...
endfor</lang>
endfor</syntaxhighlight>
We can also iterate over structures:
We can also iterate over structures:
<lang octave>x.a = [ 10, 11, 12 ];
<syntaxhighlight lang="octave">x.a = [ 10, 11, 12 ];
x.b = { "Cell", "ul", "ar" };
x.b = { "Cell", "ul", "ar" };
for [ val, key ] = x
for [ val, key ] = x
disp(key);
disp(key);
disp(val);
disp(val);
endfor</lang>
endfor</syntaxhighlight>

=={{header|Oforth}}==

<syntaxhighlight lang="oforth">: printMonths | m | Date.Months forEach: m [ m . ] ;</syntaxhighlight>

But, apply can be used instead of a loop :
<syntaxhighlight lang="oforth">#. Date.Months apply</syntaxhighlight>

=={{header|Ol}}==
<syntaxhighlight lang="scheme">
(for-each print '(1 3 4 2))
(print)
(for-each (lambda (a b c) (print a "-" b "/" c))
'(1 2 3 4)
'(5 6 7 8)
'(a b x z))
</syntaxhighlight>
{{out}}
<pre>
1
3
4
2

1-5/a
2-6/b
3-7/x
4-8/z
</pre>


=={{header|ooRexx}}==
=={{header|ooRexx}}==
The <tt>OVER</tt> loop control keyword is used to select each item in a collection in turn.
The <tt>OVER</tt> loop control keyword is used to select each item in a collection in turn.
Open Object Rexx allows the <tt>DO</tt> block structure keyword to be used to start a loop for backward compatibility with classic Rexx; the <tt>LOOP</tt> keyword is preferred here as it is self-documenting.
Open Object Rexx allows the <tt>DO</tt> block structure keyword to be used to start a loop for backward compatibility with classic Rexx; the <tt>LOOP</tt> keyword is preferred here as it is self-documenting.
<lang ooRexx>/* Rexx */
<syntaxhighlight lang="oorexx">/* Rexx */
say
say
say 'Loops/Foreach'
say 'Loops/Foreach'
Line 1,038: Line 2,284:
say out~strip()
say out~strip()


exit</syntaxhighlight>
exit
</lang>
'''Output:'''
'''Output:'''
<pre>
<pre>
Line 1,047: Line 2,292:


=={{header|Oz}}==
=={{header|Oz}}==
<lang oz>declare
<syntaxhighlight lang="oz">declare
MyList = [1 2 3 4]
MyList = [1 2 3 4]
in
in
Line 1,053: Line 2,298:


%% or:
%% or:
for E in MyList do {Show E} end</lang>
for E in MyList do {Show E} end</syntaxhighlight>


=={{header|PARI/GP}}==
=={{header|PARI/GP}}==
<lang parigp>for(i=1,#v,print(v[i]))</lang>
<syntaxhighlight lang="parigp">for(i=1,#v,print(v[i]))</syntaxhighlight>


or (PARI/GP >= 2.4)
or (PARI/GP >= 2.4)


<lang parigp>apply(x->print(x),v)</lang>
<syntaxhighlight lang="parigp">apply(x->print(x),v)</syntaxhighlight>


=={{header|Pascal}}==
=={{header|Pascal}}==
See [[Loops/Foreach#Delphi | Delphi]]
See [[Loops/Foreach#Delphi | Delphi]]

=={{header|PascalABC.NET}}==
<syntaxhighlight lang="delphi">
##
foreach var s in |'Pascal','ABC','.NET'| do
Print(s);
</syntaxhighlight>


=={{header|Perl}}==
=={{header|Perl}}==
<lang perl>foreach my $i (@collection) {
<syntaxhighlight lang="perl">foreach my $i (@collection) {
print "$i\n";
print "$i\n";
}</lang>
}</syntaxhighlight>
The keyword <code>for</code> can be used instead of <code>foreach</code>. If a loop variable (here <code>$i</code>) is not given, then <code>$_</code> is used.
The keyword <code>for</code> can be used instead of <code>foreach</code>. If a loop variable (here <code>$i</code>) is not given, then <code>$_</code> is used.


A more compact notation using perl statement modifier:
A more compact notation using perl statement modifier:
<lang perl>print "$_\n" foreach @collection</lang>
<syntaxhighlight lang="perl">print "$_\n" foreach @collection</syntaxhighlight>


In perl, it is possible to loop against an explicit list, so there is no need to define a container:
In perl, it is possible to loop against an explicit list, so there is no need to define a container:


<lang perl>foreach $l ( "apples", "bananas", "cherries" ) {
<syntaxhighlight lang="perl">foreach $l ( "apples", "bananas", "cherries" ) {
print "I like $l\n";
print "I like $l\n";
}</lang>
}</syntaxhighlight>

=={{header|Phix}}==
<!--<syntaxhighlight lang="phix">-->
<span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"field"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3.14159268979</span><span style="color: #0000FF;">,{</span><span style="color: #008000;">"this"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"that"</span><span style="color: #0000FF;">}}</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #0000FF;">?</span><span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</syntaxhighlight>-->

=={{header|PHL}}==
<syntaxhighlight lang="phl">var numbers = 1..10;


numbers each # (number) [
=={{header|Perl 6}}==
printf("%i\n", number);
{{works with|Rakudo|#21 "Seattle"}}
];</syntaxhighlight>
<lang perl6>say $_ for @collection;</lang>
Perl 6 leaves off the <tt>each</tt> from <tt>foreach</tt>, leaving us with <tt>for</tt> instead. The variable <tt>$_</tt> refers to the current element, unless you assign a name to it using <tt>-></tt>.
<lang perl6>for @collection -> $currentElement { say $currentElement; }</lang>


=={{header|PHP}}==
=={{header|PHP}}==
<lang php>foreach ($collect as $i) {
<syntaxhighlight lang="php">foreach ($collect as $i) {
echo "$i\n";
echo "$i\n";
}
}
Line 1,093: Line 2,354:
foreach ($collect as $key => $i) {
foreach ($collect as $key => $i) {
echo "\$collect[$key] = $i\n";
echo "\$collect[$key] = $i\n";
}</lang>
}</syntaxhighlight>
<code>foreach</code> can also iterate over objects. By default it iterates over all visible fields of an object.
<code>foreach</code> can also iterate over objects. By default it iterates over all visible fields of an object.


=={{header|PicoLisp}}==
=={{header|PicoLisp}}==
<lang PicoLisp>(mapc println '(Apple Banana Coconut))</lang>
<syntaxhighlight lang="picolisp">(mapc println '(Apple Banana Coconut))</syntaxhighlight>


=={{header|Pike}}==
=={{header|Pike}}==
<lang pike>int main(){
<syntaxhighlight lang="pike">int main(){
array(int|string) collect = ({109, "Hi", "asdf", "qwerty"});
array(int|string) collect = ({109, "Hi", "asdf", "qwerty"});
foreach(collect, int|string elem){
foreach(collect, int|string elem){
write(elem + "\n");
write(elem + "\n");
}
}
}</lang>
}</syntaxhighlight>
Iterating over the keys and values of a mapping (dictionary):
Iterating over the keys and values of a mapping (dictionary):
<lang pike>int main(){
<syntaxhighlight lang="pike">int main(){
mapping(string:string) coll = (["foo":"asdf", "bar":"qwer", "quux":"zxcv"]);
mapping(string:string) coll = (["foo":"asdf", "bar":"qwer", "quux":"zxcv"]);
foreach (coll;string key;string val)
foreach (coll;string key;string val)
write(key+" --> "+val+"\n");
write(key+" --> "+val+"\n");
}
}
}</lang>
}</syntaxhighlight>


=={{header|PL/I}}==
=={{header|PL/I}}==
<lang PL/I>declare A(10) fixed binary;
<syntaxhighlight lang="pli">declare A(10) fixed binary;
do i = lbound(A,1) to hbound(A,1);
do i = lbound(A,1) to hbound(A,1);
put skip list (A(i));
put skip list (A(i));
end;</lang>
end;</syntaxhighlight>

=={{header|Plain English}}==
<syntaxhighlight lang="plainenglish">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.</syntaxhighlight>
{{out}}
<pre>
1
2
3
6
7
9
</pre>


=={{header|Pop11}}==
=={{header|Pop11}}==
Iteration over list:
Iteration over list:
<lang pop11>lvars el, lst = [1 2 3 4 foo bar];
<syntaxhighlight lang="pop11">lvars el, lst = [1 2 3 4 foo bar];
for el in lst do
for el in lst do
printf(el,'%p\n');
printf(el,'%p\n');
endfor;</lang>
endfor;</syntaxhighlight>


=={{header|PostScript}}==
=={{header|PostScript}}==
The <code>forall</code> operator performs a loop over a collection (array, string or dictionary). Strings and arrays can be treated very much the same:
The <code>forall</code> operator performs a loop over a collection (array, string or dictionary). Strings and arrays can be treated very much the same:
<lang postscript>[1 5 3 2] { = } forall
<syntaxhighlight lang="postscript">[1 5 3 2] { = } forall
(abc) { = } forall</lang>
(abc) { = } forall</syntaxhighlight>
but dictionaries take a little more work since a key/value pair is pushed on the stack in each iteration:
but dictionaries take a little more work since a key/value pair is pushed on the stack in each iteration:
<lang postscript><</a 25 /b 42>> {
<syntaxhighlight lang="postscript"><</a 25 /b 42>> {
exch (Key: ) print
exch (Key: ) print
=
=
(Value: ) print
(Value: ) print
=
=
} forall</lang>
} forall</syntaxhighlight>


=={{header|PowerShell}}==
=={{header|PowerShell}}==
<lang powershell>foreach ($x in $collection) {
<syntaxhighlight lang="powershell">
$colors = "Black","Blue","Cyan","Gray","Green","Magenta","Red","White","Yellow",
Write-Host $x
"DarkBlue","DarkCyan","DarkGray","DarkGreen","DarkMagenta","DarkRed","DarkYellow"
}</lang>


foreach ($color in $colors)
=={{header|PureBasic}}==
{
Works for LinkedLists and Maps
Write-Host "$color" -ForegroundColor $color
<lang PureBasic>ForEach element()
}
PrintN(element())
</syntaxhighlight>
Next</lang>
{{Out}}
<pre>
Black
Blue
Cyan
Gray
Green
Magenta
Red
White
Yellow
DarkBlue
DarkCyan
DarkGray
DarkGreen
DarkMagenta
DarkRed
DarkYellow
</pre>

=={{header|Prolog}}==
For example :
<syntaxhighlight lang="prolog">?- foreach(member(X, [red,green,blue,black,white]), writeln(X)).
red
green
blue
black
white
true.
</syntaxhighlight>


=={{header|Python}}==
=={{header|Python}}==
<lang python>for i in collection:
<syntaxhighlight lang="python">for i in collection:
print i</lang>
print i</syntaxhighlight>

Note: The Python ''for'' statement is always a "foreach" ... and the ''range()'' and ''xrange()'' built-in functions are used to generate lists of indexes over which it will iterate as necessary. The majority of Python objects support iteration. Lists and tuples iterate over each item, strings iterate over each character, dictionaries iterate over keys, files iterate over lines, and so on.
Note: The Python <code>for</code> statement is always a ''"foreach" ...'' and the <code>range()</code> and <code>xrange()</code> built-in functions are used to generate lists of indexes over which it will iterate as necessary. The majority of Python objects support iteration. Lists and tuples iterate over each item, strings iterate over each character, dictionaries iterate over keys, files iterate over lines, and so on.


For example:
For example:
<lang python>lines = words = characters = 0
<syntaxhighlight lang="python">lines = words = characters = 0
f = open('somefile','r')
f = open('somefile','r')
for eachline in f:
for eachline in f:
Line 1,163: Line 2,502:
words += 1
words += 1
for eachchar in eachword:
for eachchar in eachword:
chracters += 1
characters += 1


print lines, words, characters</lang>
print lines, words, characters</syntaxhighlight>

Whether <code>for</code> loops over the elements of the collection in order depends on the collection having an inherent order or not. Elements of strings (i.e. characters), tuples and lists, for example, are ordered but the order of elements in dictionaries and sets is not defined.

One can loop over the key/value pairs of a dictionary in ''alphabetic'' or ''numeric'' key order by sorting the sequence of keys, provided that the keys are all of ''comparable'' types. In Python 3.x a sequence of mixed numeric and string elements is not sortable (at least not with the default invocation of <code>sorted()</code>), whereas in Python 2.x numeric types are sorted according to their string representation by default:

<syntaxhighlight lang="python">d = {3: "Earth", 1: "Mercury", 4: "Mars", 2: "Venus"}
for k in sorted(d):
print("%i: %s" % (k, d[k]))

d = {"London": "United Kingdom", "Berlin": "Germany", "Rome": "Italy", "Paris": "France"}
for k in sorted(d):
print("%s: %s" % (k, d[k]))</syntaxhighlight>

{{works with|Python|2.x}}

<syntaxhighlight lang="python">d = {"fortytwo": 42, 3.14159: "pi", 23: "twentythree", "zero": 0, 13: "thirteen"}
for k in sorted(d):
print("%s: %s" % (k, d[k]))</syntaxhighlight>

=={{header|Quackery}}==

<syntaxhighlight lang="quackery">$ "Sweet Boom Pungent Prickle Orange" nest$
witheach [ i times sp echo$ cr ]</syntaxhighlight>
{{Out}}
<pre> Sweet
Boom
Pungent
Prickle
Orange
</pre>


=={{header|R}}==
=={{header|R}}==
<lang R>a <- list("First", "Second", "Third", 5, 6)
<syntaxhighlight lang="r">a <- list("First", "Second", "Third", 5, 6)
for(i in a) print(i)</lang>
for(i in a) print(i)</syntaxhighlight>


=={{header|Racket}}==
=={{header|Racket}}==


<lang racket>
<syntaxhighlight lang="racket">
#lang racket
#lang racket


Line 1,182: Line 2,551:
(for ([i sequence])
(for ([i sequence])
(displayln i))
(displayln i))
</syntaxhighlight>
</lang>

=={{header|Raku}}==
(formerly Perl 6)
{{works with|Rakudo|2015.10-40}}
<syntaxhighlight lang="raku" line>say $_ for @collection;</syntaxhighlight>
Raku leaves off the <tt>each</tt> from <tt>foreach</tt>, leaving us with <tt>for</tt> instead. The variable <tt>$_</tt> refers to the current element, unless you assign a name to it using <tt>-></tt>.
<syntaxhighlight lang="raku" line>for @collection -> $currentElement { say $currentElement; }</syntaxhighlight>
Raku will do it's best to put the topic at the right spot.
<syntaxhighlight lang="raku" line>.say for @collection;
for @collection { .say };</syntaxhighlight>
Iteration can also be done with hyperoperators. In this case it's a candidate for autothreading and as such, execution order may vary. The resulting list will be in order.
<syntaxhighlight lang="raku" line>@collection>>.say;
@collection>>.=&infix:<+>(2); # increment each element by 2</syntaxhighlight>


=={{header|REBOL}}==
=={{header|REBOL}}==
<lang REBOL>REBOL [
<syntaxhighlight lang="rebol">REBOL [
Title: "Loop/Foreach"
Title: "Loop/Foreach"
Author: oofoe
Date: 2009-12-19
URL: http://rosettacode.org/wiki/Loop/Foreach
URL: http://rosettacode.org/wiki/Loop/Foreach
]
]
Line 1,199: Line 2,579:
; the list from the current position.
; the list from the current position.


forall x [prin rejoin [x/1 "day "]] print ""</lang>
forall x [prin rejoin [x/1 "day "]] print ""</syntaxhighlight>
Output:
Output:
<pre>Sorkday Gunday Bluesday Nedsday Thirstday Frightday Caturday
<pre>Sorkday Gunday Bluesday Nedsday Thirstday Frightday Caturday
Sorkday Gunday Bluesday Nedsday Thirstday Frightday Caturday</pre>
Sorkday Gunday Bluesday Nedsday Thirstday Frightday Caturday</pre>

=={{header|Red}}==
<syntaxhighlight lang="red">>> blk: ["John" 23 "dave" 30 "bob" 20 "Jeff" 40]
>> foreach item blk [print item]
John
23
dave
30
bob
20
Jeff
40
>> foreach [name age] blk [print [name "is" age "years old"]]
John is 23 years old
dave is 30 years old
bob is 20 years old
Jeff is 40 years old

>> forall blk [print blk]
John 23 dave 30 bob 20 Jeff 40
23 dave 30 bob 20 Jeff 40
dave 30 bob 20 Jeff 40
30 bob 20 Jeff 40
bob 20 Jeff 40
20 Jeff 40
Jeff 40
40</syntaxhighlight>

=={{header|ReScript}}==
<syntaxhighlight lang="rescript">let fruits = ["apple", "banana", "coconut"]

Js.Array2.forEach(fruits, f => Js.log(f))</syntaxhighlight>


=={{header|Retro}}==
=={{header|Retro}}==
Retro has an '''each@''' combinator for operating on elements of various data structures. A hook ('''<each@>''') exists to allow for user-defined data structures to be added.
Retro has '''for-each''' combinators for operating on elements of various data structures.

<lang Retro>( Strings: this will display the ASCII code for each character in a string )
<syntaxhighlight lang="retro"># Strings
"This is a message" [ @ putn space ] ^types'STRING each@

This will display the ASCII code for each character in a string

~~~
'This_is_a_message [ n:put sp ] s:for-each
~~~

# Array

Display each element


~~~
( Array: display each element )
{ #1 #2 #3 } [ n:put sp ] a:for-each
needs array'
~~~
[ 1 2 3 ] ^array'fromQuote [ @ putn space ] ^types'ARRAY each@


# Linked List
( Linked List: using the dictionary as an example, display each name )
last [ d->name puts space ] ^types'LIST each@


Using the dictionary as an example, display each name
( Generic Buffers; display each value in a buffer )
create foo
1 , 3 , 5 ,


~~~
foo 3 [ @ putn space ] ^types'BUFFER each@</lang>
&Dictionary [ d:name s:put sp ] d:for-each
~~~
</syntaxhighlight>


=={{header|REXX}}==
=={{header|REXX}}==
<lang rexx>days = 'zuntik montik dinstik mitvokh donershtik fraytik shabes'
<syntaxhighlight lang="rexx">days = 'zuntik montik dinstik mitvokh donershtik fraytik shabes'


do j=1 for words(days) /*loop through days of the week. */
do j=1 for words(days) /*loop through days of the week. */
say word(days,j) /*display the weekday to screen. */
say word(days,j) /*display the weekday to screen. */
end /*j*/
end /*j*/
lang postscript> /*stick a fork in it, we're done.*/</lang>
/*stick a fork in it, we're done.*/</syntaxhighlight>

=={{header|Ring}}==
<syntaxhighlight lang="ring">
aList = "Welcome to the Ring Programming Language"
for n in aList
see n + nl
next
</syntaxhighlight>

=={{header|RPL}}==
In RPL, « printing » a collection means sending it to the printer, if you have one. To just output the items of a list, you put them into the stack, like this:
≪ { "one" "two" "three" "four" "five" } LIST→ DROP ≫
If the idea is to do more than displaying the items, the usual way is a <code>FOR..NEXT</code> loop
≪ { "one" "two" "three" "four" "five" } → collection
≪ 1 collection SIZE '''FOR''' j
collection j GET
''(do something with the item here)''
'''NEXT'''
≫ ≫


=={{header|Ruby}}==
=={{header|Ruby}}==
<lang ruby>for i in collection do
<syntaxhighlight lang="ruby">for i in collection do
puts i
puts i
end</lang>
end</syntaxhighlight>
This is syntactic sugar for:
This is syntactic sugar for:
<lang ruby>collection.each do |i|
<syntaxhighlight lang="ruby">collection.each do |i|
puts i
puts i
end</lang>
end</syntaxhighlight>
There are various flavours of <code>each</code> that may be class-dependent: [http://www.ruby-doc.org/core/classes/String.html#M000862 String#each_char], [http://www.ruby-doc.org/core/classes/Array.html#M002174 Array#each_index], [http://www.ruby-doc.org/core/classes/Hash.html#M002863 Hash#each_key], etc
There are various flavours of <code>each</code> that may be class-dependent: [http://www.ruby-doc.org/core/classes/String.html#M000862 String#each_char], [http://www.ruby-doc.org/core/classes/Array.html#M002174 Array#each_index], [http://www.ruby-doc.org/core/classes/Hash.html#M002863 Hash#each_key], etc


=={{header|Rust}}==
Rust's for-loop already is a foreach-loop.
<syntaxhighlight lang="rust">let collection = vec![1,2,3,4,5];
for elem in collection {
println!("{}", elem);
}</syntaxhighlight>


Do note that Rust moves values by default and doesn't copy them. A vector would be unusable after looping over it like above. To preserve it, borrow it or use an Iter, to mutate values do a mutable borrow or create an IterMut. To get an immutable reference omit the mut-part.
=={{header|Run BASIC}}==
<syntaxhighlight lang="rust">let mut collection = vec![1,2,3,4,5];
<lang runbasic>t$={Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday"
for mut_ref in &mut collection {
// alternatively:
// for mut_ref in collection.iter_mut() {
*mut_ref *= 2;
println!("{}", *mut_ref);
}


// immutable borrow
while word$(t$,i+1,",") <> ""
for immut_ref in &collection {
i = i + 1
// alternatively:
print word$(t$,i,",")
// for immut_ref in collection.iter() {
wend</lang>
println!("{}", *immut_ref);
}</syntaxhighlight>

Since Rust 1.21 foreach can be used explicitly executing a closure on each element.
<syntaxhighlight lang="rust">let collection = vec![1, 2, 3, 4, 5];
collection.iter().for_each(|elem| println!("{}", elem));</syntaxhighlight>


=={{header|Salmon}}==
=={{header|Salmon}}==
<lang Salmon>iterate (x; ["Red", "Green", "Blue"])
<syntaxhighlight lang="salmon">iterate (x; ["Red", "Green", "Blue"])
x!;</lang>
x!;</syntaxhighlight>
output:
output:
<pre>
<pre>
Line 1,260: Line 2,719:


=={{header|SAS}}==
=={{header|SAS}}==
<lang sas>/* Initialize an array with integers 1 to 10, and print their sum */
<syntaxhighlight lang="sas">/* Initialize an array with integers 1 to 10, and print their sum */
data _null_;
data _null_;
array a a1-a10;
array a a1-a10;
Line 1,270: Line 2,729:
s=sum(of a{*});
s=sum(of a{*});
put s;
put s;
run;</lang>
run;</syntaxhighlight>


=={{header|Sather}}==
=={{header|Sather}}==
<lang sather>class MAIN is
<syntaxhighlight lang="sather">class MAIN is
main is
main is
num:ARRAY{INT} := |1, 5, 4, 3, 10|;
num:ARRAY{INT} := |1, 5, 4, 3, 10|;
Line 1,282: Line 2,741:
end;
end;
end;
end;
end;</lang>
end;</syntaxhighlight>


=={{header|Scala}}==
=={{header|Scala}}==
<lang scala>val collection = Array(1, 2, 3, 4)
<syntaxhighlight lang="scala">val collection = Array(1, 2, 3, 4)
collection.foreach(println)</syntaxhighlight>
for (element <- collection)
println(element)</lang>
Alternatively:
Alternatively:
<lang scala>for (element <- 1 to 4)
<syntaxhighlight lang="scala">(element <- 1 to 4).foreach(println)</syntaxhighlight>
println(element)</lang>


=={{header|Scheme}}==
=={{header|Scheme}}==
List:
List:
<lang scheme>(for-each
<syntaxhighlight lang="scheme">(for-each
(lambda (i) (display i) (newline))
(lambda (i) (display i) (newline))
the_list)</lang>
the_list)</syntaxhighlight>

=={{header|Scilab}}==
{{works with|Scilab|5.5.1}}
<syntaxhighlight lang="text">for e=["a","b","c"]
printf("%s\n",e)
end</syntaxhighlight>
{{out}}
<pre>a
b
c</pre>


=={{header|Seed7}}==
=={{header|Seed7}}==
The for loop of Seed7 can be used to loop over the elements of a container.
The for loop of Seed7 can be used to loop over the elements of a container.
<lang seed7>$ include "seed7_05.s7i";
<syntaxhighlight lang="seed7">$ include "seed7_05.s7i";


var array string: things is [] ("Apple", "Banana", "Coconut");
var array string: things is [] ("Apple", "Banana", "Coconut");
Line 1,311: Line 2,778:
writeln(thing);
writeln(thing);
end for;
end for;
end func;</lang>
end func;</syntaxhighlight>

=={{header|Self}}==
<syntaxhighlight lang="self">aCollection do: [| :element | element printLine ].</syntaxhighlight>
(Provided that the objects in the collection understand the <code>printLine</code> method).

=={{header|SETL}}==
<syntaxhighlight lang="setl">S := {1,2,3,5,8,13,21,34,55,89};
for e in S loop
print(e);
end loop;</syntaxhighlight>

=={{header|Sidef}}==
'''foreach''' loop:
<syntaxhighlight lang="ruby">foreach [1,2,3] { |i|
say i
}</syntaxhighlight>

'''for-in''' loop:
<syntaxhighlight lang="ruby">for i in [1,2,3] {
say i
}</syntaxhighlight>

'''.each''' method:
<syntaxhighlight lang="ruby">[1,2,3].each { |i|
say i
}</syntaxhighlight>


=={{header|Slate}}==
=={{header|Slate}}==
<lang slate>c do: [| :obj | print: obj].</lang>
<syntaxhighlight lang="slate">c do: [| :obj | print: obj].</syntaxhighlight>


=={{header|Smalltalk}}==
=={{header|Smalltalk}}==
<lang smalltalk>aCollection do: [ :element | element displayNl ].</lang>
<syntaxhighlight lang="smalltalk">aCollection do: [ :element | element displayNl ].</syntaxhighlight>
(Provided that the objects in the collection understand the <code>displayNl</code> method).
Provided that the objects in the collection understand the <code>displayNl</code> method (which can be added, if missing).

Most modern Smalltalks allow for a selector symbol to be sent a <tt>value:</tt> message; which allows for the very compact:
<syntaxhighlight lang="smalltalk">aCollection do:#displayNl.</syntaxhighlight>

(and because Aikido mentions it: of course this works for any kind of collection (and even things which simply implement a <tt>do:</tt> method to iterate on something)
<syntaxhighlight lang="smalltalk">(1 to:6 by:2) do:#displayNl.
'hello' do:#displayNl.
(Integer primesUpTo:100) do:#displayNl.
'/' asFilename directoryContents do:#displayNl.
((Smalltalk allClasses collect:#name) asSortedCollection to:2) do:#displayNl.

funnyClassLessObject := Plug new
respondTo:#do:
with:[:arg |
arg value:'look ma'.
arg value:'no classes needed'].
funnyClassLessObject do:#displayNl.
etc.</syntaxhighlight>
{{out}}
1
3
5
h
e
l
l
o
2
3
5
...
97
home
usr
...
tmp
cores
AAAARecord
AATree
look ma
no classes needed

=={{header|Snabel}}==
Prints foo, bar & baz followed by newlines.
<syntaxhighlight lang="snabel">['foo' 'bar' 'baz'] &say for</syntaxhighlight>

=={{header|Sparkling}}==

Sparkling currently has no "foreach" construct, but there's a "foreach" function in the standard library:

<syntaxhighlight lang="sparkling">let hash = { "foo": 42, "bar": 1337, "baz": "qux" };
foreach(hash, function(key, val) {
print(key, " -> ", val);
});</syntaxhighlight>


=={{header|Standard ML}}==
=={{header|Standard ML}}==
List of integers:
List of integers:
<lang sml>app
<syntaxhighlight lang="sml">app
(fn i => print (Int.toString i ^ "\n"))
(fn i => print (Int.toString i ^ "\n"))
collect_list</lang>
collect_list</syntaxhighlight>
Array of integers:
Array of integers:
<lang sml>Array.app
<syntaxhighlight lang="sml">Array.app
(fn i => print (Int.toString i ^ "\n"))
(fn i => print (Int.toString i ^ "\n"))
collect_array</lang>
collect_array</syntaxhighlight>

=={{header|Stata}}==
<syntaxhighlight lang="stata">local a 2 9 4 7 5 3 6 1 8
foreach i in `a' {
display "`i'"
}</syntaxhighlight>


=={{header|Suneido}}==
=={{header|Suneido}}==
<lang Suneido>for i in #(1, 2, 3)
<syntaxhighlight lang="suneido">for i in #(1, 2, 3)
Print(i)</lang>
Print(i)</syntaxhighlight>

=={{header|Swift}}==
<syntaxhighlight lang="swift">for i in [1,2,3] {
print(i)
}</syntaxhighlight>
This works for any type that conforms to the <code>SequenceType</code> protocol (including arrays, collections, generators, ranges).

Alternately:
{{works with|Swift|2.x+}}
<syntaxhighlight lang="swift">[1,2,3].forEach {
print($0)
}</syntaxhighlight>


=={{header|SystemVerilog}}==
=={{header|SystemVerilog}}==
<lang SystemVerilog>program main;
<syntaxhighlight lang="systemverilog">program main;
int values[$];
int values[$];


Line 1,344: Line 2,909:
end
end
end
end
endprogram</lang>
endprogram</syntaxhighlight>

=={{header|Tailspin}}==
Stream them
<syntaxhighlight lang="tailspin">
['a', 'b', 'c'] ... -> !OUT::write
</syntaxhighlight>
{{out}}
<pre>abc</pre>

Lists/arrays can be put through an array transform to get the index as well
<syntaxhighlight lang="tailspin">
['a', 'b', 'c'] -> \[i]('$i;:$;
' -> !OUT::write \) -> !VOID
</syntaxhighlight>
{{out}}
<pre>
1:a
2:b
3:c
</pre>


=={{header|Tcl}}==
=={{header|Tcl}}==
<lang tcl>foreach i {foo bar baz} {
<syntaxhighlight lang="tcl">foreach i {foo bar baz} {
puts "$i"
puts "$i"
}</lang>
}</syntaxhighlight>
Note that <tt>foreach</tt> also accepts multiple variables:
Note that <tt>foreach</tt> also accepts multiple variables:
<lang tcl>foreach {x y} {1 2 3 4} {
<syntaxhighlight lang="tcl">foreach {x y} {1 2 3 4} {
puts "$x,$y"
puts "$x,$y"
}</lang>
}</syntaxhighlight>
And also multiple lists:
And also multiple lists:
<lang tcl>foreach i {1 2 3} j {a b c} {
<syntaxhighlight lang="tcl">foreach i {1 2 3} j {a b c} {
puts "$i,$j"
puts "$i,$j"
}</lang>
}</syntaxhighlight>
Or any combination of variables/list:
Or any combination of variables/list:
<lang tcl>foreach i {1 2 3} {x y} {a b c d e f} {
<syntaxhighlight lang="tcl">foreach i {1 2 3} {x y} {a b c d e f} {
puts "$i,$x,$y"
puts "$i,$x,$y"
}</lang>
}</syntaxhighlight>

=={{header|TI-89 BASIC}}==
<lang ti89b>Local i,strs
Define strs = {"Lorem","ipsum","dolor"}
For i, 1, dim(strs)
Disp strs[i]
EndFor</lang>


=={{header|Trith}}==
=={{header|Trith}}==
<lang trith>[1 2 3 4 5] [print] each</lang>
<syntaxhighlight lang="trith">[1 2 3 4 5] [print] each</syntaxhighlight>


=={{header|TUSCRIPT}}==
=={{header|TUSCRIPT}}==
<lang tuscript>$$ MODE TUSCRIPT
<syntaxhighlight lang="tuscript">$$ MODE TUSCRIPT
week="Monday'Tuesday'Wednesday'Thursday'Friday'Saterday'Sunday"
week="Monday'Tuesday'Wednesday'Thursday'Friday'Saterday'Sunday"
LOOP day=week
LOOP day=week
PRINT day
PRINT day
ENDLOOP</lang>
ENDLOOP</syntaxhighlight>
Output:
Output:
<pre>
<pre>
Line 1,393: Line 2,971:
To iterate any single list, you use a <code>for</code> loop.
To iterate any single list, you use a <code>for</code> loop.
{{works with|Bourne Shell}}
{{works with|Bourne Shell}}
<lang bash>for file in *.sh; do
<syntaxhighlight lang="bash">for file in *.sh; do
echo "filename is $file"
echo "filename is $file"
done</lang>
done</syntaxhighlight>
If the list is in a shell parameter (like <code>PATH</code>), you adjust <code>IFS</code>.
If the list is in a shell parameter (like <code>PATH</code>), you adjust <code>IFS</code>.
{{works with|Bourne Shell}}
{{works with|Bourne Shell}}
<lang bash>PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin
<syntaxhighlight lang="bash">PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin


oldifs=$IFS
oldifs=$IFS
Line 1,405: Line 2,983:
echo search $dir
echo search $dir
done
done
IFS=$oldifs</lang>
IFS=$oldifs</syntaxhighlight>
Some shells have real arrays. The <code>for</code> loop can also iterate these.
Some shells have real arrays. The <code>for</code> loop can also iterate these.
{{works with|Bash}}
{{works with|Bash}}
<lang bash>collection=("first" "second" "third" "fourth" "something else")
<syntaxhighlight lang="bash">collection=("first" "second" "third" "fourth" "something else")
for x in "${collection[@]}"; do
for x in "${collection[@]}"; do
echo "$x"
echo "$x"
done</lang>
done</syntaxhighlight>
{{works with|pdksh|5.2.14}}
{{works with|pdksh|5.2.14}}
<lang bash>set -A collection "first" "second" "third" "fourth" "something else"
<syntaxhighlight lang="bash">set -A collection "first" "second" "third" "fourth" "something else"
for x in "${collection[@]}"; do
for x in "${collection[@]}"; do
echo "$x"
echo "$x"
done</lang>
done</syntaxhighlight>


==={{header|C Shell}}===
==={{header|C Shell}}===
<lang csh>set collection=(first second third fourth "something else")
<syntaxhighlight lang="csh">set collection=(first second third fourth "something else")
foreach x ($collection:q)
foreach x ($collection:q)
echo $x:q
echo $x:q
end</lang>
end</syntaxhighlight>


=={{header|V}}==
=={{header|V}}==
<lang v>[1 2 3] [puts] step</lang>
<syntaxhighlight lang="v">[1 2 3] [puts] step</syntaxhighlight>


=={{header|VBScript}}==
=={{header|Vala}}==
<syntaxhighlight lang="vala">List<string> things = new List<string> ();
<lang vbscript>dim items(2)
items(0)="Apple"
things.append("Apple");
things.append("Banana");
items(1)="Orange"
things.append("Coconut");
items(2)="Banana"
foreach (string thing in things)
{
stdout.printf("%s\n", thing);
}</syntaxhighlight>


=={{header|Vim Script}}==
For Each x in items
Vim Script's for-loop is actually a foreach-loop and iterates through a list.
WScript.Echo x
<syntaxhighlight lang="vim">for i in ["alpha", "beta", 42, 5.54]
Next</lang>
echo i
endfor</syntaxhighlight>


=={{header|Visual Basic .NET}}==
=={{header|V (Vlang)}}==
{{trans|go}}
<lang vbnet>Dim list As New List(Of String)

list.Add("Car")
<syntaxhighlight lang="v (vlang)">fn print_all(values []int) {
list.Add("Boat")
for i, x in values {
list.Add("Train")
println("Item $i = $x")
}
For Each item In list
}</syntaxhighlight>
Console.WriteLine(item)

Next</lang>
=={{header|Wart}}==
<syntaxhighlight lang="wart">each x '(1 2 3)
prn x</syntaxhighlight>

=={{header|WDTE}}==
<syntaxhighlight lang="wdte">let a => import 'arrays';
let s => import 'stream';

a.stream [5; 7; 3]
-> s.map (io.writeln io.stdout)
-> s.drain
;</syntaxhighlight>

=={{header|Wren}}==
<syntaxhighlight lang="wren">for (f in ["apples", "oranges", "pears"]) System.print(f)</syntaxhighlight>

{{out}}
<pre>
apples
oranges
pears
</pre>

=={{header|XLISP}}==
XLISP's <tt>FOR-EACH</tt> applies a procedure to each member of a list in turn.
<syntaxhighlight lang="lisp">(FOR-EACH PRINT '(CYRUS CAMBYSES DARIUS XERXES ARTAXERXES))</syntaxhighlight>
{{out}}
<pre>CYRUS
CAMBYSES
DARIUS
XERXES
ARTAXERXES</pre>


=={{header|XPL0}}==
=={{header|XPL0}}==
Translation of C example:
Translation of C example:
<lang XPL0>include c:\cxpl\codes;
<syntaxhighlight lang="xpl0">include c:\cxpl\codes;
int List, I;
int List, I;
[List:= ["Red", "Green", "Blue", "Black", "White"];
[List:= ["Red", "Green", "Blue", "Black", "White"];
for I:= 0, 5-1 do
for I:= 0, 5-1 do
[Text(0, List(I)); CrLf(0)];
[Text(0, List(I)); CrLf(0)];
]</lang>
]</syntaxhighlight>


=={{header|XSLT}}==
=={{header|XSLT}}==
For-each is the only iteration construct that is built into XSLT. All other iteration is either implied by applying a template to all members matching an XPath expression, or built from recursive application of a template. You have access to something like a loop counter with the one-based "position()" function.
For-each is the only iteration construct that is built into XSLT. All other iteration is either implied by applying a template to all members matching an XPath expression, or built from recursive application of a template. You have access to something like a loop counter with the one-based "position()" function.
<lang xml><fo:block font-weight="bold">Adults:</fo:block>
<syntaxhighlight lang="xml"><fo:block font-weight="bold">Adults:</fo:block>
<xsl:for-each select="person[@age &gt;= 21]">
<xsl:for-each select="person[@age &gt;= 21]">
<fo:block><xsl:value-of select="position()"/>. <xsl:value-of select="@name"/></fo:block>
<fo:block><xsl:value-of select="position()"/>. <xsl:value-of select="@name"/></fo:block>
</xsl:for-each></lang>
</xsl:for-each></syntaxhighlight>

=={{header|zig}}==
<syntaxhighlight lang="zig">const warn = @import("std").debug.warn;
pub fn main() void {
const items = [_]i16{ 0, 1, 1, 2, 3, 5, 8 };
for (items) |i| {
warn("{}\n", .{i});
}
}
</syntaxhighlight>

=={{header|zkl}}==
{{trans|XPL0}}
<syntaxhighlight lang="zkl">foreach c in (T("Red","Green","Blue","Black","White"))
{ print(c," "); }</syntaxhighlight>
{{out}}
<pre>Red Green Blue Black White</pre>
Other forms of foreach, one that breaks apart a container into elements and one line nested loops.
<syntaxhighlight lang="zkl">foreach x,y,z in (T(T(1,2,3), T(4,5,6))) { println(x,y,z) }
foreach x,y,z in (T(1,2,3), T(4,5), T(6)){ println(x,y,z) }</syntaxhighlight>
{{out}}
<pre>
123
456
</pre>
<pre>
146
156
246
256
346
356
</pre>

=={{header|Zig}}==
<syntaxhighlight lang="zig">const std = @import("std");

pub fn main() !void {
const stdout_wr = std.io.getStdOut().writer();

// 1. Index element index sizes are comptime-known
const a1: []const u8 = &[_]u8{ 'a', 'b', 'c' };
// also works with slices
//const a2: [] u8 = &a1;
for (a1) |el_a|
try stdout_wr.print("{c}\n", .{el_a});
// 2. Index element index sizes are not comptime-known
// Convention is to provide a `next()` method.
// TODO
}</syntaxhighlight>


{{omit from|GUISS}}
{{omit from|GUISS}}
{{omit from|PL/0}}
{{omit from|Tiny BASIC}}
Retrieved from "https://rosettacode.org/wiki/Loops/Foreach"