View source for Apply a callback to an array

[[Category:Iteration]]
{{task|Basic language learning}}

;Task:
Take a combined set of elements and apply a function to each element.
<br><br>

=={{header|11l}}==
{{trans|Kotlin}}
<syntaxhighlight lang="11l">V array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
V arrsq = array.map(i -> i * i)
print(arrsq)</syntaxhighlight>
{{out}}
<pre>[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]</pre>

=={{header|6502 Assembly}}==
For this example, assume both the source array and the destination have a size of 86 elements (memory offsets base+0x00 to base+0x55.)
This was implemented in easy6502.
<syntaxhighlight lang="6502asm">define SRC_LO  $00
define SRC_HI  $01

define DEST_LO $02
define DEST_HI $03

define temp $04		;temp storage used by foo

;some prep work since easy6502 doesn't allow you to define arbitrary bytes before runtime.

SET_TABLE:
TXA
STA $1000,X
INX
BNE SET_TABLE	
;stores the identity table at memory address $1000-$10FF

CLEAR_TABLE:
LDA #0
STA $1200,X
INX
BNE CLEAR_TABLE
;fills the range $1200-$12FF with zeroes.


LDA #$10
STA SRC_HI
LDA #$00
STA SRC_LO
;store memory address $1000 in zero page

LDA #$12
STA DEST_HI
LDA #$00
STA DEST_LO
;store memory address $1200 in zero page


loop:
LDA (SRC_LO),y  ;load accumulator from memory address $1000+y
JSR foo		;multiplies accumulator by 3.
STA (DEST_LO),y ;store accumulator in memory address $1200+y

INY
CPY #$56 ;alternatively you can store a size variable and check that here instead.
BCC loop
BRK

foo:
STA temp
ASL		;double accumulator
CLC
ADC temp	;2a + a = 3a
RTS</syntaxhighlight>



{{out}}
<pre>
1200: 00 03 06 09 0c 0f 12 15 18 1b 1e 21 24 27 2a 2d 
1210: 30 33 36 39 3c 3f 42 45 48 4b 4e 51 54 57 5a 5d 
1220: 60 63 66 69 6c 6f 72 75 78 7b 7e 81 84 87 8a 8d 
1230: 90 93 96 99 9c 9f a2 a5 a8 ab ae b1 b4 b7 ba bd 
1240: c0 c3 c6 c9 cc cf d2 d5 d8 db de e1 e4 e7 ea ed 
1250: f0 f3 f6 f9 fc ff
</pre>

=={{header|68000 Assembly}}==
{{trans|11l}}
The following assumes all code/data is stored/executed in RAM and is therefore mutable.
<syntaxhighlight lang="68000devpac">LEA MyArray,A0
MOVE.W #(MyArray_End-MyArray)-1,D7  ;Len(MyArray)-1
MOVEQ #0,D0 ;sanitize D0-D2 to ensure nothing from any previous work will affect our math.
MOVEQ #0,D1
MOVEQ #0,D2

loop:
MOVE.B (A0),D0
MOVE.B D0,D1
MOVE.B D0,D2
MULU D1,D2
MOVE.B D2,(A0)+
dbra d7,loop
jmp *       ;halt the CPU

MyArray:
DC.B 1,2,3,4,5,6,7,8,9,10
MyArray_End:</syntaxhighlight>


=={{header|8th}}==
The builtin word "a:map" does this:
<syntaxhighlight lang="forth">
[ 1 , 2, 3 ]
' n:sqr
a:map
</syntaxhighlight>
That results in the array [1,4,9]

=={{header|ACL2}}==

ACL2 does not have first-class functions; this is close, however:

<syntaxhighlight lang="lisp">(defun apply-to-each (xs)
   (if (endp xs)
       nil
       (cons (fn-to-apply (first xs))
             (sq-each (rest xs)))))

(defun fn-to-apply (x)
   (* x x))
</syntaxhighlight>

=={{header|ActionScript}}==
<syntaxhighlight lang="actionscript">package
{
    public class ArrayCallback
    {
        public function main():void
        {
            var nums:Array = new Array(1, 2, 3);
            nums.map(function(n:Number, index:int, arr:Array):void { trace(n * n * n); });
            
            // You can also pass a function reference
            nums.map(cube);
        }
        
        private function cube(n:Number, index:int, arr:Array):void
        {
            trace(n * n * n);
        }
    }
}</syntaxhighlight>

=={{header|Ada}}==
{{works with|GNAT|GPL 2005}}
<syntaxhighlight lang="ada">with Ada.Text_Io;
 with Ada.Integer_text_IO;
 
 procedure Call_Back_Example is
    -- Purpose: Apply a callback to an array
    -- Output: Prints the squares of an integer array to the console
   
    -- Define the callback procedure
    procedure Display(Location : Positive; Value : Integer) is
    begin
       Ada.Text_Io.Put("array(");
       Ada.Integer_Text_Io.Put(Item => Location, Width => 1);
       Ada.Text_Io.Put(") = ");
       Ada.Integer_Text_Io.Put(Item => Value * Value, Width => 1);
       Ada.Text_Io.New_Line;
    end Display;
   
    -- Define an access type matching the signature of the callback procedure
    type Call_Back_Access is access procedure(L : Positive; V : Integer);
   
    -- Define an unconstrained array type
    type Value_Array is array(Positive range <>) of Integer;
   
    -- Define the procedure performing the callback
    procedure Map(Values : Value_Array; Worker : Call_Back_Access) is
    begin
       for I in Values'range loop
          Worker(I, Values(I));
       end loop;
    end Map;
   
    -- Define and initialize the actual array
    Sample : Value_Array := (5,4,3,2,1);
   
 begin
    Map(Sample, Display'access);   
 end Call_Back_Example;</syntaxhighlight>

=={{header|Aime}}==
<syntaxhighlight lang="aime">void
map(list l, void (*fp)(object))
{
    l.ucall(fp, 0);
}

void
out(object o)
{
    o_(o, "\n");
}

integer
main(void)
{
    list(0, 1, 2, 3).map(out);

    return 0;
}</syntaxhighlight>

=={{header|ALGOL 68}}==
{{works with|ALGOL 68|Revision 1 - no extensions to language used}}

{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-1.18.0/algol68g-1.18.0-9h.tiny.el5.centos.fc11.i386.rpm/download 1.18.0-9h.tiny]}}
{{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of FORMATted transput}}
<syntaxhighlight lang="algol68"> PROC call back proc = (INT location, INT value)VOID:
 (
   printf(($"array["g"] = "gl$, location, value))
 );

 PROC map = (REF[]INT array, PROC (INT,INT)VOID call back)VOID:
 (
   FOR i FROM LWB array TO UPB array DO
      call back(i, array[i])
   OD
 );
 
 main:
 (
   [4]INT array := ( 1, 4, 9, 16 );
   map(array, call back proc)
 )</syntaxhighlight>

{{Out}}
<pre>
array[         +1] =          +1
array[         +2] =          +4
array[         +3] =          +9
array[         +4] =         +16
</pre>

=={{header|ALGOL W}}==
<syntaxhighlight lang="algolw">begin
    procedure printSquare ( integer value x ) ; writeon( i_w := 1, s_w := 0, " ", x * x );
    % applys f to each element of a from lb to ub (inclusive) %
    procedure applyI ( procedure f; integer array a ( * ); integer value lb, ub ) ;
        for i := lb until ub do f( a( i ) );
    % test applyI %
    begin
        integer array a ( 1 :: 3 );
        a( 1 ) := 1; a( 2 ) := 2; a( 3 ) := 3;
        applyI( printSquare, a, 1, 3 )
    end
end.</syntaxhighlight>

=={{header|APL}}==
By default functions in APL work on arrays as it is an array oriented language. Some examples:

<syntaxhighlight lang="apl">    - 1 2 3
¯1 ¯2 ¯3
    2 * 1 2 3 4
2 4 8 16
    2 × ⍳4
2 4 6 8
    3 * 3 3 ⍴ ⍳9
   3    9    27
  81  243   729
2187 6561 19683
</syntaxhighlight>

=={{header|AppleScript}}==
<syntaxhighlight lang="applescript">on callback for arg
    -- Returns a string like "arc has 3 letters"
    arg & " has " & (count arg) & " letters"
end callback

set alist to {"arc", "be", "circle"}
repeat with aref in alist
    -- Passes a reference to some item in alist
    -- to callback, then speaks the return value.
    say (callback for aref)
end repeat</syntaxhighlight>

If the callback would <code>set arg's contents to "something"</code>, then <code>alist</code> would be mutated.


For a more general implementation of '''map(function, list)''', '''foldl(function, startValue, list)''', and '''filter(predicate, list)''', we could write:

<syntaxhighlight lang="applescript">on run
    
    set xs to {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
    
    {map(square, xs), ¬
        filter(even, xs), ¬
        foldl(add, 0, xs)}
    
    --> {{1, 4, 9, 16, 25, 36, 49, 64, 81, 100}, {2, 4, 6, 8, 10}, 55}  
    
end run

-- square :: Num -> Num -> Num
on square(x)
    x * x
end square

-- add :: Num -> Num -> Num
on add(a, b)
    a + b
end add

-- even :: Int -> Bool
on even(x)
    0 = x mod 2
end even


-- GENERIC HIGHER ORDER FUNCTIONS

-- filter :: (a -> Bool) -> [a] -> [a]
on filter(f, xs)
    tell mReturn(f)
        set lst to {}
        set lng to length of xs
        repeat with i from 1 to lng
            set v to item i of xs
            if |λ|(v, i, xs) then set end of lst to v
        end repeat
        return lst
    end tell
end filter

-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
    tell mReturn(f)
        set v to startValue
        set lng to length of xs
        repeat with i from 1 to lng
            set v to |λ|(v, item i of xs, i, xs)
        end repeat
        return v
    end tell
end foldl

-- Lift 2nd class handler function into 1st class script wrapper 
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
    if class of f is script then
        f
    else
        script
            property |λ| : f
        end script
    end if
end mReturn

-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
    tell mReturn(f)
        set lng to length of xs
        set lst to {}
        repeat with i from 1 to lng
            set end of lst to |λ|(item i of xs, i, xs)
        end repeat
        return lst
    end tell
end map</syntaxhighlight>
{{Out}}
<pre>{{1, 4, 9, 16, 25, 36, 49, 64, 81, 100}, {2, 4, 6, 8, 10}, 55}</pre>

=={{header|Arturo}}==
<syntaxhighlight lang="rebol">arr: [1 2 3 4 5]

print map arr => [2*&]</syntaxhighlight>
    
{{out}}

<pre>2 4 6 8 10</pre>

=={{header|AutoHotkey}}==
<syntaxhighlight lang="autohotkey">map("callback", "3,4,5")

callback(array){
  Loop, Parse, array, `,
    MsgBox % (2 * A_LoopField)
}
 
map(callback, array){
  %callback%(array)
}</syntaxhighlight>

=={{header|AWK}}==
<syntaxhighlight lang="awk">$ awk 'func psqr(x){print x,x*x}BEGIN{split("1 2 3 4 5",a);for(i in a)psqr(a[i])}'
4 16
5 25
1 1
2 4
3 9</syntaxhighlight>

=={{header|Babel}}==

Let us define a squaring operator:

<syntaxhighlight lang="babel">sq { dup * } <</syntaxhighlight>

Now, we apply the sq operator over a list and display the result using the lsnum utility:

<syntaxhighlight lang="babel">( 0 1 1 2 3 5 8 13 21 34 ) { sq ! } over ! lsnum !</syntaxhighlight>

{{Out}}
<pre>( 0 1 1 4 9 25 64 169 441 1156 )</pre>

=={{header|BBC BASIC}}==
{{works with|BBC BASIC for Windows}}
<syntaxhighlight lang="bbcbasic">      DIM a(4)
      a() = 1, 2, 3, 4, 5
      PROCmap(a(), FNsqrt())
      FOR i = 0 TO 4
        PRINT a(i)
      NEXT
      END
      
      DEF FNsqrt(n) = SQR(n)
      
      DEF PROCmap(array(), RETURN func%)
      LOCAL I%
      FOR I% = 0 TO DIM(array(),1)
        array(I%) = FN(^func%)(array(I%))
      NEXT
      ENDPROC
</syntaxhighlight>
{{Out}}
<pre>
         1
1.41421356
1.73205081
         2
2.23606798
</pre>

=={{header|Binary Lambda Calculus}}==
In the lambda calculus, we can map over a list as in https://github.com/tromp/AIT/blob/master/lists/map.lam, which gives the following BLC program to negate every bit of input:
<pre>010001101000000101100000000001011000000101111111010110010111111101111110111010</pre>

=={{header|BQN}}==
<syntaxhighlight lang="bqn">Square ← ×˜

array ← 2‿3‿5‿7‿11‿13

Square¨ array</syntaxhighlight>
The use of the ¨ modifier is the general approach, but actually not necessary with arithmetic functions.
{{out}}
<pre>⟨ 4 9 25 49 121 169 ⟩</pre>

=={{header|Bracmat}}==
<syntaxhighlight lang="bracmat">( ( callbackFunction1
  =   location value
    .   !arg:(?location,?value)
      & out$(str$(array[ !location "] = " !!value))
  )
& ( callbackFunction2
  =   location value
    .   !arg:(?location,?value)
      & !!value^2:?!value
  )
& ( mapar
  =   arr len callback i
    .   !arg:(?arr,?len,?callback)
      & 0:?i
      &   whl
        ' ( !i:<!len
          & !callback$(!i,!i$!arr)
          & 1+!i:?i
          )
  )
& tbl$(array,4)
& 1:?(0$array)
& 2:?(1$array)
& 3:?(2$array)
& 4:?(3$array)
& mapar$(array,4,callbackFunction1)
& mapar$(array,4,callbackFunction2)
& mapar$(array,4,callbackFunction1)
);</syntaxhighlight>
{{Out}}
<pre>array[0] = 1
array[1] = 2
array[2] = 3
array[3] = 4
array[0] = 1
array[1] = 4
array[2] = 9
array[3] = 16</pre>

=={{header|Brat}}==

<syntaxhighlight lang="brat">#Print out each element in array
[:a :b :c :d :e].each { element |
	p element
}</syntaxhighlight>

Alternatively:

<syntaxhighlight lang="brat">[:a :b :c :d :e].each ->p</syntaxhighlight>

=={{header|C}}==

'''callback.h'''
<syntaxhighlight lang="c">#ifndef CALLBACK_H
#define CALLBACK_H

/*
 * By declaring the function in a separate file, we allow
 * it to be used by other source files.
 *
 * It also stops ICC from complaining.
 *
 * If you don't want to use it outside of callback.c, this
 * file can be removed, provided the static keyword is prepended
 * to the definition.
 */
void map(int* array, int len, void(*callback)(int,int));

#endif</syntaxhighlight>

'''callback.c'''
<syntaxhighlight lang="c">#include <stdio.h>
#include "callback.h"

/*
 * We don't need this function outside of this file, so
 * we declare it static.
 */
static void callbackFunction(int location, int value)
{
  printf("array[%d] = %d\n", location, value);
} 

void map(int* array, int len, void(*callback)(int,int))
{
  int i;
  for(i = 0; i < len; i++)
  {
     callback(i, array[i]);
  }
} 

int main()
{
  int array[] = { 1, 2, 3, 4 };
  map(array, 4, callbackFunction);
  return 0;
}</syntaxhighlight>

{{Out}}
<pre>
  array[0] = 1
  array[1] = 2
  array[2] = 3
  array[3] = 4
</pre>

=={{header|C sharp|C#}}==
{{works with|C sharp|C#|3.0+}}
This version uses the C# 3 lambda notation. 

<syntaxhighlight lang="csharp">int[] intArray = { 1, 2, 3, 4, 5 };
// Simplest method:  LINQ, functional
int[] squares1 = intArray.Select(x => x * x).ToArray();

// Slightly fancier: LINQ, query expression
int[] squares2 = (from x in intArray
                  select x * x).ToArray();

// Or, if you only want to call a function on each element, just use foreach
foreach (var i in intArray)
    Console.WriteLine(i * i);</syntaxhighlight>

{{works with|C sharp|C#|2.0+}}

{{works with|Visual C sharp|Visual C#|2005}}
<syntaxhighlight lang="csharp">using System; 

static class Program
{
  // Purpose: Apply a callback (or anonymous method) to an Array
  // Output: Prints the squares of an int array to the console.
  // Compiler: Visual Studio 2005
  // Framework: .net 2
   
  [STAThread]
  public static void Main() 
  {
    int[] intArray = { 1, 2, 3, 4, 5 };

    // Using a callback,
    Console.WriteLine("Printing squares using a callback:");
    Array.ForEach<int>(intArray, PrintSquare);

    // or using an anonymous method:
    Console.WriteLine("Printing squares using an anonymous method:");
    Array.ForEach<int>
    (
      intArray,
      delegate(int value) 
      {
        Console.WriteLine(value * value);    
      });
  }

  public static void PrintSquare(int value) 
  { 
    Console.WriteLine(value * value);
  }
}</syntaxhighlight>

=={{header|C++}}==

{{works with|g++|4.1.1}}    
===C-Style Array===
<syntaxhighlight lang="cpp">#include <iostream> //cout for printing
#include <algorithm> //for_each defined here

//create the function (print the square)
void print_square(int i) {
  std::cout << i*i << " ";
}

int main() {
  //create the array
  int ary[]={1,2,3,4,5};
  //stl for_each
  std::for_each(ary,ary+5,print_square);
  return 0;
}
//prints 1 4 9 16 25</syntaxhighlight>

===std::vector===
{{libheader|STL}}
<syntaxhighlight lang="cpp">#include <iostream>  // cout for printing
#include <algorithm> // for_each defined here
#include <vector>    // stl vector class

// create the function (print the square)
void print_square(int i) {
  std::cout << i*i << " ";
}

int main() {
  // create the array
  std::vector<int> ary;
  ary.push_back(1);
  ary.push_back(2);
  ary.push_back(3);
  ary.push_back(4);
  ary.push_back(5);
  // stl for_each
  std::for_each(ary.begin(),ary.end(),print_square);
  return 0;
}
//prints 1 4 9 16 25</syntaxhighlight>

More tricky with binary function
<syntaxhighlight lang="cpp">#include <iostream>   // cout for printing
#include <algorithm>  // for_each defined here
#include <vector>     // stl vector class
#include <functional> // bind and ptr_fun

// create a binary function (print any two arguments together)
template<class type1,class type2>
void print_juxtaposed(type1 x, type2 y) {
  std::cout << x << y;
}

int main() {
  // create the array
  std::vector<int> ary;
  ary.push_back(1);
  ary.push_back(2);
  ary.push_back(3);
  ary.push_back(4);
  ary.push_back(5);
  // stl for_each, using binder and adaptable unary function
  std::for_each(ary.begin(),ary.end(),std::bind2nd(std::ptr_fun(print_juxtaposed<int,std::string>),"x "));
  return 0;
}
//prints 1x 2x 3x 4x 5x</syntaxhighlight>

===Boost.Lambda===
{{libheader|Boost}}
<syntaxhighlight lang="cpp">using namespace std;
using namespace boost::lambda;
vector<int> ary(10);
int i = 0;
for_each(ary.begin(), ary.end(), _1 = ++var(i)); // init array
transform(ary.begin(), ary.end(), ostream_iterator<int>(cout, " "), _1 * _1); // square and output</syntaxhighlight>

===C++11===
<syntaxhighlight lang="cpp">#include <vector>
#include <iostream>
#include <algorithm>
#include <iterator>

int main() {
   std::vector<int> intVec(10);
   std::iota(std::begin(intVec), std::end(intVec), 1 ); // Fill the vector
   std::transform(std::begin(intVec) , std::end(intVec), std::begin(intVec),
	 [](int i) { return i * i ; } ); // Transform it with closures
   std::copy(std::begin(intVec), end(intVec) ,
	 std::ostream_iterator<int>(std::cout, " "));
   std::cout << std::endl;
   return 0;
}</syntaxhighlight>

=={{header|Clean}}==

Define a function and an initial (unboxed) array.

<syntaxhighlight lang="clean">square x = x * x

values :: {#Int}
values = {x \\ x <- [1 .. 10]}</syntaxhighlight>

One can easily define a map for arrays, which is overloaded and works for all kinds of arrays (lazy, strict, unboxed).

<syntaxhighlight lang="clean">mapArray f array = {f x \\ x <-: array}</syntaxhighlight>

Apply the function to the initial array (using a comprehension) and print result.

<syntaxhighlight lang="clean">Start :: {#Int}
Start = mapArray square values</syntaxhighlight>

=={{header|Clio}}==
'''Math operations'''
<syntaxhighlight lang="clio">[1 2 3 4] * 2 + 1 -> print</syntaxhighlight>
'''Quick functions'''
<syntaxhighlight lang="text">[1 2 3 4] -> * n: n * 2 + 1 -> print</syntaxhighlight>
'''Anonymous function'''
<syntaxhighlight lang="clio">[1 2 3 4]
  -> * fn n:
     n * 2 + 1
  -> print</syntaxhighlight>
'''Named function'''
<syntaxhighlight lang="clio">fn double-plus-one n:
  n * 2 + 1

[1 2 3 4] -> * double-plus-one -> print</syntaxhighlight>

=={{header|Clojure}}==

<syntaxhighlight lang="lisp">;; apply a named function, inc
(map inc [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="lisp">;; apply a function
(map (fn [x] (* x x)) [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="lisp">;; shortcut syntax for a function
(map #(* % %) [1 2 3 4])</syntaxhighlight>

=={{header|CLU}}==
<syntaxhighlight lang="clu">% This procedure will call a given procedure with each element
% of the given array. Thanks to CLU's type parameterization,
% it will work for any type of element.
apply_to_all = proc [T: type] (a: array[T], f: proctype(int,T))
    for i: int in array[T]$indexes(a) do
        f(i, a[i])
    end
end apply_to_all

% Callbacks for both string and int
show_int = proc (i, val: int)
    po: stream := stream$primary_output()
    stream$putl(po, "array[" || int$unparse(i) || "] = " || int$unparse(val));
end show_int

show_string = proc (i: int, val: string)
    po: stream := stream$primary_output()
    stream$putl(po, "array[" || int$unparse(i) || "] = " || val);
end show_string

% Here's how to use them
start_up = proc () 
    po: stream := stream$primary_output()
    
    ints: array[int] := array[int]$[2, 3, 5, 7, 11]
    strings: array[string] := array[string]$
        ["enemy", "lasagna", "robust", "below", "wax"]
    
    stream$putl(po, "Ints: ")
    apply_to_all[int](ints, show_int)
    
    stream$putl(po, "\nStrings: ")
    apply_to_all[string](strings, show_string)
end start_up</syntaxhighlight>
{{out}}
<pre>Ints:
array[1] = 2
array[2] = 3
array[3] = 5
array[4] = 7
array[5] = 11

Strings:
array[1] = enemy
array[2] = lasagna
array[3] = robust
array[4] = below
array[5] = wax</pre>

=={{header|COBOL}}==
{{Works with|COBOL 2002}}
Basic implementation of a map function:
<syntaxhighlight lang="cobolfree">       >>SOURCE FORMAT IS FREE
IDENTIFICATION DIVISION.
PROGRAM-ID. map.

DATA DIVISION.
LOCAL-STORAGE SECTION.
01  i                  USAGE IS INDEX.
01  table-size         CONSTANT AS 30.
LINKAGE SECTION.
01  table-param.
    03 table-values    USAGE IS FLOAT-LONG, OCCURS table-size TIMES.
01  func-ptr           USAGE IS PROGRAM-POINTER.

PROCEDURE DIVISION USING BY REFERENCE table-param, BY VALUE func-ptr.
    PERFORM VARYING i FROM 1 BY 1 UNTIL i IS GREATER THAN table-size
        CALL func-ptr USING BY REFERENCE table-values(i)
    END-PERFORM
    GOBACK.

END PROGRAM map.</syntaxhighlight>

=={{header|CoffeeScript}}==
<syntaxhighlight lang="coffeescript">
map = (arr, f) -> (f(e) for e in arr)
arr = [1, 2, 3, 4, 5]
f = (x) -> x * x
console.log map arr, f # prints [1, 4, 9, 16, 25]
</syntaxhighlight>

=={{header|Common Lisp}}==

Imperative: print 1, 2, 3, 4 and 5:

<syntaxhighlight lang="lisp">(map nil #'print #(1 2 3 4 5))</syntaxhighlight>

Functional: collect squares into new vector that is returned:

<syntaxhighlight lang="lisp">(defun square (x) (* x x))
(map 'vector #'square #(1 2 3 4 5))</syntaxhighlight>

Destructive, like the Javascript example; add 1 to every slot of vector *a*:

<syntaxhighlight lang="lisp">(defvar *a* (vector 1 2 3))
(map-into *a* #'1+ *a*)</syntaxhighlight>

=={{header|Component Pascal}}==
BlackBox Component Builder
<syntaxhighlight lang="oberon2">
MODULE Callback;
IMPORT StdLog;

TYPE
	Callback = PROCEDURE (x: INTEGER;OUT doubled: INTEGER);
	Callback2 = PROCEDURE (x: INTEGER): INTEGER;
	
	PROCEDURE Apply(proc: Callback; VAR x: ARRAY OF INTEGER);
	VAR
		i: INTEGER;
	BEGIN
		FOR i := 0 TO LEN(x) - 1 DO;
			proc(x[i],x[i]);
		END
	END Apply;
	
	PROCEDURE Apply2(func: Callback2; VAR x: ARRAY OF INTEGER);
	VAR
		i: INTEGER;
	BEGIN
		FOR i := 0 TO LEN(x) - 1 DO;
			x[i] := func(x[i]);
		END
	END Apply2;
	
	PROCEDURE Double(x: INTEGER; OUT y: INTEGER);
	BEGIN	
		y := x * x;
	END Double;
	
	PROCEDURE Double2(x: INTEGER): INTEGER;
	BEGIN
		RETURN x * x
	END Double2;
	
	PROCEDURE Do*;
	VAR
		i: INTEGER;
		ary: ARRAY 10 OF INTEGER;
		
		
	BEGIN
		FOR i := 0 TO LEN(ary) - 1 DO ary[i] := i END;
		Apply(Double,ary);
		FOR i := 0 TO LEN(ary) - 1 DO
			StdLog.Int(ary[i]);StdLog.Ln
		END;
		StdLog.Ln;
		Apply2(Double2,ary);
		FOR  i := 0 TO LEN(ary) - 1 DO
		        StdLog.Int(ary[i]);StdLog.Ln
		END
	END Do;
END Callback.
</syntaxhighlight>
Execute: ^Q Callback.Do<br/>
{{Out}}
<pre>
 0
 1
 4
 9
 16
 25
 36
 49
 64
 81

 0
 1
 16
 81
 256
 625
 1296
 2401
 4096
 6561
</pre>

=={{header|Crystal}}==
Calling with a block
<syntaxhighlight lang="ruby">values = [1, 2, 3]

new_values = values.map do |number|
  number * 2
end

puts new_values  #=> [2, 4, 6]</syntaxhighlight>

Calling with a function/method
<syntaxhighlight lang="ruby">values = [1, 2, 3]

def double(number)
  number * 2
end

# the `->double(Int32)` syntax creates a proc from a function/method. argument types must be specified.
# the `&proc` syntax passes a proc as a block.
# combining the two passes a function/method as a block
new_values = values.map &->double(Int32)

puts new_values  #=> [2, 4, 6]</syntaxhighlight>

=={{header|D}}==
<syntaxhighlight lang="d">import std.stdio, std.algorithm;

void main() {
    auto items = [1, 2, 3, 4, 5];
    auto m = items.map!(x => x + 5)();
    writeln(m);
}</syntaxhighlight>
{{out}}
<pre>[6, 7, 8, 9, 10]</pre>

=={{header|Delphi}}==
<syntaxhighlight lang="delphi">
// Declare the callback function
procedure callback(const AInt:Integer);
begin
  WriteLn(AInt);
end;

const
  // Declare a static array
  myArray:Array[0..4] of Integer=(1,4,6,8,7);
var
  // Declare interator variable
  i:Integer;
begin
  // Iterate the array and apply callback
  for i:=0 to length(myArray)-1 do
    callback(myArray[i]);
end.
</syntaxhighlight>

=={{header|Dyalect}}==

<syntaxhighlight lang="dyalect">func Array.Select(pred) {
    let ys = []
    for x in this when pred(x) {
        ys.Add(x)
    }
    return ys
}
 
var arr = [1, 2, 3, 4, 5]
var squares = arr.Select(x => x * x)
 
print(squares)</syntaxhighlight>

=={{header|Déjà Vu}}==
There is a <code>map</code> builtin that does just this.
<syntaxhighlight lang="dejavu">!. map @++ [ 1 4 8 ]

#implemented roughly like this:
#map f lst:
#    ]
#    for i in lst:
#         f i
#    [</syntaxhighlight>
{{out}}
<pre>[ 2 5 9 ]</pre>

=={{header|E}}==

<syntaxhighlight lang="e">def array := [1,2,3,4,5]
def square(value) { 
    return value * value
}</syntaxhighlight>

Example of builtin iteration:

<syntaxhighlight lang="e">def callback(index, value) { 
    println(`Item $index is $value.`)
}
array.iterate(callback)</syntaxhighlight>

There is no built-in map function '''yet'''. 
The following is one of the ways one could be implemented, 
returning a plain list (which is usually an array in implementation).

<syntaxhighlight lang="e">def map(func, collection) {
    def output := [].diverge()
    for item in collection {
        output.push(func(item))
    }
    return output.snapshot()
}
println(map(square, array))</syntaxhighlight>

=={{header|EchoLisp}}==
<syntaxhighlight lang="scheme">
(vector-map sqrt #(0 4 16 49))
    → #( 0 2 4 7)
;; or
(map exp #(0 1 2))
    → #( 1 2.718281828459045 7.38905609893065)
;; or
(for/vector ([elem #(2 3 4)] [i (in-naturals)]) (printf "v[%d] = %a" i elem) (* elem elem))
v[0] = 2
v[1] = 3
v[2] = 4
    → #( 4 9 16)
</syntaxhighlight>

=={{header|Efene}}==

<syntaxhighlight lang="efene">square = fn (N) {
    N * N
}

# list comprehension
squares1 = fn (Numbers) {
    [square(N) for N in Numbers]
}

# functional form
squares2a = fn (Numbers) {
    lists.map(fn square:1, Numbers)
}

# functional form with lambda
squares2b = fn (Numbers) {
    lists.map(fn (N) { N * N }, Numbers)
}

# no need for a function
squares3 = fn (Numbers) {
    [N * N for N in Numbers]
}

@public
run = fn () {
    Numbers = [1, 3, 5, 7]
    io.format("squares1 : ~p~n", [squares1(Numbers)])
    io.format("squares2a: ~p~n", [squares2a(Numbers)])
    io.format("squares2b: ~p~n", [squares2b(Numbers)])
    io.format("squares3 : ~p~n", [squares3(Numbers)])
}
</syntaxhighlight>

=={{header|EGL}}==
<syntaxhighlight lang="egl">delegate callback( i int ) returns( int ) end

program ApplyCallbackToArray
	function main()
		values int[] = [ 1, 2, 3, 4, 5 ];

		func callback = square;
		for ( i int to values.getSize() )
			values[ i ] = func( values[ i ] );
		end
		
		for ( i int to values.getSize() )
			SysLib.writeStdout( values[ i ] );
		end
	end
	
	function square( i int ) returns( int )
		return( i * i );
	end
end</syntaxhighlight>

=={{header|Elena}}==
ELENA 6.x :
<syntaxhighlight lang="elena">import system'routines;

PrintSecondPower(n){ console.writeLine(n * n) }

public program()
{
    new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}.forEach(PrintSecondPower)
}</syntaxhighlight>

=={{header|Elixir}}==
<syntaxhighlight lang="elixir">
Enum.map([1, 2, 3], fn(n) -> n * 2 end)
Enum.map [1, 2, 3], &(&1 * 2)
</syntaxhighlight>

{{Out}}
<pre>
[2, 4, 6]
</pre>

=={{header|Erlang}}==
A list would be more commonly used in Erlang rather than an array.

<syntaxhighlight lang="erlang">
1> L = [1,2,3].
[1,2,3]
</syntaxhighlight>

You can use lists:foreach/2 if you just want to apply the callback to each element of the list.

<syntaxhighlight lang="text">
2> lists:foreach(fun(X) -> io:format("~w ",[X]) end, L).
1 2 3 ok
</syntaxhighlight>

Or you can use lists:map/2 if you want to create a new list with the result of the callback on each element.

<syntaxhighlight lang="erlang">
3> lists:map(fun(X) -> X + 1 end, L).
[2,3,4]
</syntaxhighlight>

Or you can use lists:foldl/3 if you want to accumulate the result of the callback on each element into one value.

<syntaxhighlight lang="erlang">
4> lists:foldl(fun(X, Sum) -> X + Sum end, 0, L).
6
</syntaxhighlight>

=={{header|ERRE}}==
<syntaxhighlight lang="text">
PROGRAM CALLBACK

!
! for rosettacode.org
!

DIM A[5]

FUNCTION CBACK(X)
   CBACK=2*X-1
END FUNCTION

PROCEDURE PROCMAP(ZETA,DUMMY(X)->OUTP)
   OUTP=DUMMY(ZETA)
END PROCEDURE

BEGIN
   A[1]=1  A[2]=2   A[3]=3  A[4]=4  A[5]=5
   FOR I%=1 TO 5 DO
      PROCMAP(A[I%],CBACK(X)->OUTP)
      PRINT(OUTP;)
   END FOR
   PRINT
END PROGRAM
</syntaxhighlight>
This example shows how to pass a function to a procedure.
{{Out}}
<pre>
  1  3  5  7  9
</pre>

=={{header|Euphoria}}==
<syntaxhighlight lang="euphoria">function apply_to_all(sequence s, integer f)
    -- apply a function to all elements of a sequence
    sequence result
    result = {}
    for i = 1 to length(s) do
	-- we can call add1() here although it comes later in the program
	result = append(result, call_func(f, {s[i]}))
    end for
    return result
end function

function add1(atom x)
    return x + 1
end function

-- add1() is visible here, so we can ask for its routine id
? apply_to_all({1, 2, 3}, routine_id("add1"))
-- displays {2,3,4}</syntaxhighlight>
This is also "Example 2" in the Euphoria documentation for <code>routine_id()</code>.
Note that this example will not work for multi-dimensional sequences.

=={{header|F_Sharp|F#}}==
Apply a named function to each member of the array. The result is a new array of the same size as the input.
<syntaxhighlight lang="fsharp">let evenp x = x % 2 = 0
let result = Array.map evenp [| 1; 2; 3; 4; 5; 6 |]</syntaxhighlight>
The same can be done using anonymous functions, this time squaring the members of the input array.
<syntaxhighlight lang="fsharp">let result = Array.map (fun x -> x * x) [|1; 2; 3; 4; 5|]</syntaxhighlight>
Use ''iter'' if the applied function does not return a value.
<syntaxhighlight lang="fsharp">Array.iter (fun x -> printfn "%d" x) [|1; 2; 3; 4; 5|]</syntaxhighlight>

=={{header|Factor}}==
Print each element squared:
<syntaxhighlight lang="factor">{ 1 2 3 4 } [ sq . ] each</syntaxhighlight>

Collect return values:
<syntaxhighlight lang="factor">{ 1 2 3 4 } [ sq ] map</syntaxhighlight>

=={{header|Fantom}}==

In Fantom, functions can be passed to a collection iterator, such as 'each'.  'map' is used similarly, and the results are collected into a list.

<syntaxhighlight lang="fantom">
class Main
{
  public static Void main ()
  {
    [1,2,3,4,5].each |Int i| { echo (i) }
    Int[] result := [1,2,3,4,5].map |Int i->Int| { return i * i }
    echo (result) 
  }
}
</syntaxhighlight>

{{Out}}
<pre>
1
2
3
4
5
[1, 4, 9, 16, 25]
</pre>

=={{header|FBSL}}==
'''User-defined mapping function:'''
<syntaxhighlight lang="qbasic">#APPTYPE CONSOLE

FOREACH DIM e IN MyMap(Add42, {1, 2, 3})
	PRINT e, " ";
NEXT

PAUSE

FUNCTION MyMap(f, a)
	DIM ret[]
	FOREACH DIM e IN a
		ret[] = f(e)
	NEXT
	RETURN ret
END FUNCTION

FUNCTION Add42(n): RETURN n + 42: END FUNCTION</syntaxhighlight>
{{Out}}
<pre>43 44 45
Press any key to continue...</pre>

'''Standard MAP() function:'''
<syntaxhighlight lang="qbasic">#APPTYPE CONSOLE

DIM languages[] = {{"English", {"one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"}}, _
		  {"French", {"un", "deux", "trois", "quatre", "cinq", "six", "sept", "huit", "neuf", "dix"}}}

MAP(SpeakALanguage, languages)

PAUSE

SUB NameANumber(lang, nb, number)
	PRINT "The number ", nb, " is called ", STRENC(number), " in ", lang
END SUB

SUB SpeakALanguage(lang)
	MAP(NameANumber, lang[0], 1 TO 10, lang[1])
	PRINT LPAD("", 40, "-")
END SUB</syntaxhighlight>
{{Out}}
<pre>The number 1 is called "one" in English
The number 2 is called "two" in English
The number 3 is called "three" in English
The number 4 is called "four" in English
The number 5 is called "five" in English
The number 6 is called "six" in English
The number 7 is called "seven" in English
The number 8 is called "eight" in English
The number 9 is called "nine" in English
The number 10 is called "ten" in English
----------------------------------------
The number 1 is called "un" in French
The number 2 is called "deux" in French
The number 3 is called "trois" in French
The number 4 is called "quatre" in French
The number 5 is called "cinq" in French
The number 6 is called "six" in French
The number 7 is called "sept" in French
The number 8 is called "huit" in French
The number 9 is called "neuf" in French
The number 10 is called "dix" in French
----------------------------------------
Press any key to continue...</pre>

=={{header|Fe}}==
<syntaxhighlight lang="clojure">
(= map (fn (f lst)
  (let res (cons nil nil))
  (let tail res)
  (while lst
    (setcdr tail (cons (f (car lst)) nil))
    (= lst (cdr lst))
    (= tail (cdr tail)))
  (cdr res)))

(print (map (fn (x) (* x x)) '(1 2 3 4 5 6 7 8 9 10)))
</syntaxhighlight>

=={{header|Forth}}==

This is a word that will call a given function on each cell in an array.

<syntaxhighlight lang="forth">: map ( addr n fn -- )
   -rot cells bounds do  i @ over execute i !  cell +loop ;</syntaxhighlight>

{{Out|Example usage}}
<syntaxhighlight lang="forth">create data 1 , 2 , 3 , 4 , 5 ,
data 5 ' 1+ map  \ adds one to each element of data</syntaxhighlight>

=={{header|Fortran}}==
Elemental functions.

{{Works with |Fortran|ISO 95 and later}}
<syntaxhighlight lang="fortran">module arrCallback
contains
    elemental function cube( x )
        implicit none
        real :: cube
        real, intent(in) :: x
        cube = x * x * x
    end function cube
end module arrCallback</syntaxhighlight>

<syntaxhighlight lang="fortran">program testAC
    use arrCallback
    implicit none
    integer :: i, j
    real, dimension(3,4) :: b, &
        a = reshape( (/ ((10 * i + j, i = 1, 3), j = 1, 4) /), (/ 3,4 /) )
     
    do i = 1, 3
        write(*,*) a(i,:)
    end do
     
    b = cube( a )  ! Applies CUBE to every member of a,
                   ! and stores each result in the equivalent element of b
    do i = 1, 3
        write(*,*) b(i,:)
    end do
end program testAC</syntaxhighlight>

{{Works with|ANSI FORTRAN| 77 (with MIL-STD-1753 structured DO) and later}}
<syntaxhighlight lang="fortran">      program test
C
C--   Declare array:
      integer a(5)
C
C--   Fill it with Data
      data a /45,22,67,87,98/
C
C--   Do something with all elements (in this case: print their squares)
      do i=1,5
        print *,a(i)*a(i)
      end do
C
      end</syntaxhighlight>

=={{header|FP}}==
<syntaxhighlight lang="fp">{square * . [id, id]}
& square: <1,2,3,4,5></syntaxhighlight>

=={{header|FreeBASIC}}==
<syntaxhighlight lang="freebasic">' FB 1.05.0 Win64

Sub PrintEx(n As Integer)
  Print n, n * n, n * n * n
End Sub

Sub Proc(a() As Integer, callback As Sub(n As Integer))
  For i As Integer = LBound(a) To UBound(a)
    callback(i)
  Next
End Sub

Dim a(1 To 10) As Integer = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
Print " n", "n^2", "n^3"
Print " -", "---", "---"
Proc(a(), @PrintEx)
Print
Print "Press any key to quit the program"
Sleep</syntaxhighlight>

{{out}}
<pre>
 n            n^2           n^3
 -            ---           ---
 1             1             1
 2             4             8
 3             9             27
 4             16            64
 5             25            125
 6             36            216
 7             49            343
 8             64            512
 9             81            729
 10            100           1000
</pre>

=={{header|Frink}}==
<syntaxhighlight lang="frink">
f = {|x| x^2}   // Anonymous function to square input
a = [1,2,3,5,7]
println[map[f, a]]
</syntaxhighlight>

=={{header|FunL}}==
<syntaxhighlight lang="funl">[1, 2, 3].foreach( println )

[1, 2, 3].foreach( a -> println(2a) )</syntaxhighlight>

{{out}}

<pre>
1
2
3
2
4
6
</pre>

=={{header|Futhark}}==
<syntaxhighlight lang="futhark">
map f l
</syntaxhighlight>
e.g.
<syntaxhighlight lang="futhark">
map (\x->x+1) [1,2,3] -- [2,3,4]
</syntaxhighlight>
or equivalently
<syntaxhighlight lang="futhark">
map (+1) [1,2,3] -- [2,3,4]
</syntaxhighlight>


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

include "NSLog.incl"

void local fn Callback( n as NSInteger )
  NSLog( @"Square root of %ld = %f", n, sqr(n) )
end fn

void local fn DoIt
  NSUInteger i, count
  CFArrayRef array = @[@1, @2, @3, @4, @5, @6, @7, @8, @9, @10]

  count = len(array)
  
  for i = 0 to count -1
    fn Callback( fn NumberIntegerValue( array[i] ) )
  next
end fn

fn DoIt

HandleEvents
</syntaxhighlight>

Another option is to enumerate the array.
<syntaxhighlight lang="futurebasic">include "NSLog.incl"

void local fn Callback( array as CFArrayRef, obj as CFTypeRef )
  long value = intVal(obj)
  NSLog( @"Square root of %ld = %f", value, sqr(value) )
end fn

void local fn DoIt
  CFArrayRef array = @[@1, @2, @3, @4, @5, @6, @7, @8, @9, @10]
  ArrayEnumerateObjects( array, @fn Callback, NULL )
end fn

fn DoIt

HandleEvents</syntaxhighlight>

{{out}}
<pre>
Square root of 1 = 1.000000
Square root of 2 = 1.414214
Square root of 3 = 1.732051
Square root of 4 = 2.000000
Square root of 5 = 2.236068
Square root of 6 = 2.449490
Square root of 7 = 2.645751
Square root of 8 = 2.828427
Square root of 9 = 3.000000
Square root of 10 = 3.162278
</pre>

=={{header|Fōrmulæ}}==

{{FormulaeEntry|page=https://formulae.org/?script=examples/Apply_a_callback_to_an_array}}

'''Solution'''

Most programming languages define a high-order map function. In Fōrmulæ, there is ''arraization'' (by analogy with ''summation''). In the following expression, the "big" curly braces resembles the "big" sigma of a summation:

[[File:Fōrmulæ - Apply a callback to an array 01.png]]

[[File:Fōrmulæ - Apply a callback to an array 02.png]]

The elements of the array are not required to be of the same type:

[[File:Fōrmulæ - Apply a callback to an array 03.png]]

[[File:Fōrmulæ - Apply a callback to an array 04.png]]

=={{header|GAP}}==
<syntaxhighlight lang="gap">a := [1 .. 4];
b := ShallowCopy(a);

# Apply and replace values
Apply(a, n -> n*n);
a;
# [ 1, 4, 9, 16 ]

# Apply and don't change values
List(b, n -> n*n);
# [ 1, 4, 9, 16 ]

# Apply and don't return anything (only side effects)
Perform(b, Display);
1
2
3
4

b;
# [ 1 .. 4 ]</syntaxhighlight>

=={{header|Go}}==
{{trans|Ruby}}
The task was originally written with a Ruby example, so here are Go versions of the current Ruby examples.

Perhaps in contrast to Ruby, it is idiomatic in Go to use the for statement:
<syntaxhighlight lang="go">package main

import "fmt"

func main() {
    for _, i := range []int{1, 2, 3, 4, 5} {
        fmt.Println(i * i)
    }
}</syntaxhighlight>

Alternatively though, an array-like type can be defined and callback-style methods can be defined on it to apply a function to the elements.
<syntaxhighlight lang="go">package main

import "fmt"

type intSlice []int

func (s intSlice) each(f func(int)) {
    for _, i := range s {
        f(i)
    }
}

func (s intSlice) Map(f func(int) int) intSlice {
    r := make(intSlice, len(s))
    for j, i := range s {
        r[j] = f(i)
    }
    return r
}

func main() {
    s := intSlice{1, 2, 3, 4, 5}

    s.each(func(i int) {
        fmt.Println(i * i)
    })

    fmt.Println(s.Map(func(i int) int {
        return i * i
    }))
}</syntaxhighlight>
{{out}}
<pre>
1
4
9
16
25
[1 4 9 16 25]
</pre>

=={{header|Groovy}}==

Print each value in a list
<syntaxhighlight lang="groovy">[1,2,3,4].each { println it }</syntaxhighlight>

Create a new list containing the squares of another list
<syntaxhighlight lang="groovy">[1,2,3,4].collect { it * it }</syntaxhighlight>

=={{header|Haskell}}==

===List===
{{works with|GHC}}
<syntaxhighlight lang="haskell">let square x = x*x
let values = [1..10]
map square values</syntaxhighlight>

Using list comprehension to generate a list of the squared values
<syntaxhighlight lang="haskell">[square x | x <- values]</syntaxhighlight>

More directly
<syntaxhighlight lang="haskell">[1 .. 10] >>= pure . (^ 2)</syntaxhighlight>

Or with one less layer of monadic wrapping
<syntaxhighlight lang="haskell">(^ 2) <$> [1..10]</syntaxhighlight>

Using function composition to create a function that will print the squares of a list
<syntaxhighlight lang="haskell">let printSquares = mapM_ (print.square)
printSquares values</syntaxhighlight>

===Array===
{{works with|GHC|7.10.3}}
<syntaxhighlight lang="haskell">import Data.Array (Array, listArray)

square :: Int -> Int
square x = x * x

values :: Array Int Int
values = listArray (1, 10) [1 .. 10]

main :: IO ()
main = print $ fmap square values</syntaxhighlight>
{{Out}}
<pre>array (1,10) [(1,1),(2,4),(3,9),(4,16),(5,25),(6,36),(7,49),(8,64),(9,81),(10,100)]</pre>

=={{header|Guish}}==
{{works with|guish|2.5.1}}
<syntaxhighlight lang="guish">
# applies add2 (adds 2) to each element
add2 = {
    return add(@1, 2)
}
l = {1, 2, 3, 4, 5, 6, 7}
puts each(add2, flat(@l))
</syntaxhighlight>

=={{header|Icon}} and {{header|Unicon}}==
<syntaxhighlight lang="icon">procedure main()
   local lst
   lst := [10, 20, 30, 40]
   every callback(write,!lst)
end

procedure callback(p,arg)
   return p(" -> ", arg)
end</syntaxhighlight>

=={{header|IDL}}==

Hard to come up with an example that isn't completely contrived. IDL doesn't really distinguish between a scalar and an array; thus

<syntaxhighlight lang="idl">b = a^3</syntaxhighlight>

will yield a scalar if <tt>a</tt> is scalar or a vector if <tt>a</tt> is a vector or an n-dimensional array if <tt>a</tt> is an n-dimensional array

=={{header|Insitux}}==

<syntaxhighlight lang="insitux">; apply a named function
(map inc [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="insitux">; apply a parameterised closure
(map (fn x (+ x 1)) [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="insitux">; apply a non-parameterised closure
(map #(+ % 1) [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="insitux">; apply an explicit partial closure
(map @(+ 1) [1 2 3 4])</syntaxhighlight>

<syntaxhighlight lang="insitux">; apply an implicit partial closure
(map (+ 1) [1 2 3 4])</syntaxhighlight>

=={{header|Io}}==
<syntaxhighlight lang="io">list(1,2,3,4,5) map(squared)</syntaxhighlight>

=={{header|J}}==

'''Solution''':
<syntaxhighlight lang="j">   "_1</syntaxhighlight>

'''Example''':
<syntaxhighlight lang="j">   callback =:  *:
   array    =:  1 2 3 4 5
   
   callback"_1 array
1 4 9 16 25</syntaxhighlight>

But note that this is a trivial example since <code>*: 1 2 3 4 5</code> would get the same result.  Then again, this is something of a trivial exercise in J since all of J is designed around the idea of applying functions usefully to arrays.

=={{header|Jakt}}==
<syntaxhighlight lang="jakt">
fn map<T, U>(anon array: [T], function: fn(anon x: T) -> U) throws -> [U] {
    mut result: [U] = []
    result.ensure_capacity(array.size())
    for item in array {
        result.push(value: function(item))
    }
    return result
}

fn main() {
    let array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
    let array_squared = map(array, function: fn(anon n: i64) => n * n)
    println("{}", array_squared)
}
</syntaxhighlight>

{{out}}
<pre>
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
</pre>

=={{header|Java}}==

Up to Java 7, you have to define an interface for each type of function you want to use.
The <code>IntConsumer</code> performs an action (which doesn't return anything) on an array of ints,
while the <code>IntToInt</code> is used to replace the array values.

<syntaxhighlight lang="java">public class ArrayCallback7 {

    interface IntConsumer {
        void run(int x);
    }

    interface IntToInt {
        int run(int x);
    }

    static void forEach(int[] arr, IntConsumer consumer) {
        for (int i : arr) {
            consumer.run(i);
        }
    }

    static void update(int[] arr, IntToInt mapper) {
        for (int i = 0; i < arr.length; i++) {
            arr[i] = mapper.run(arr[i]);
        }
    }

    public static void main(String[] args) {
        int[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

        forEach(numbers, new IntConsumer() {
            public void run(int x) {
                System.out.println(x);
            }
        });

        update(numbers, new IntToInt() {
            @Override
            public int run(int x) {
                return x * x;
            }
        });

        forEach(numbers, new IntConsumer() {
            public void run(int x) {
                System.out.println(x);
            }
        });
    }
}</syntaxhighlight>

Using Java 8 streams:
{{works with|Java|8}}

<syntaxhighlight lang="java">import java.util.Arrays;

public class ArrayCallback {

    public static void main(String[] args) {
        int[] myIntArray = {1, 2, 3, 4, 5};

        int sum = Arrays.stream(myIntArray)
                .map(x -> {
                    int cube = x * x * x;
                    System.out.println(cube);
                    return cube;
                })
                .reduce(0, (left, right) -> left + right); // <-- could substitute .sum() for .reduce(...) here.
        System.out.println("sum: " + sum);
    }
}</syntaxhighlight>

=={{header|JavaScript}}==

===ES3===
<syntaxhighlight lang="javascript">function map(a, func) {
  var ret = [];
  for (var i = 0; i < a.length; i++) {
    ret[i] = func(a[i]);
  }
  return ret;
}

map([1, 2, 3, 4, 5], function(v) { return v * v; });</syntaxhighlight>

===ES5===
<syntaxhighlight lang="javascript">[1, 2, 3, 4, 5].map(function(v) { return v * v; });</syntaxhighlight>

===ES6===
<syntaxhighlight lang="javascript">[1, 2, 3, 4, 5].map(v => v * v);</syntaxhighlight>

The result is always: 

<pre>[1, 4, 9, 16, 25]</pre>

=={{header|Joy}}==
<syntaxhighlight lang="joy">[1 2 3 4 5] [dup *] map.</syntaxhighlight>

=={{header|jq}}==
<syntaxhighlight lang="jq"># Illustration of map/1 using the builtin filter: exp
map(exp)  # exponentiate each item in the input list

# A compound expression can be specified as the argument to map, e.g.
map( (. * .) + sqrt ) # x*x + sqrt(x)

# The compound expression can also be a composition of filters, e.g.
map( sqrt|floor )     # the floor of the sqrt

# Array comprehension
reduce .[] as $n ([]; . + [ exp ])

# Elementwise operation 
 [.[] + 1 ]   # add 1 to each element of the input array
</syntaxhighlight>Here is a transcript illustrating how the last of these jq expressions can be evaluated:
<syntaxhighlight lang="jq">$ jq -c ' [.[] + 1 ]'
[0, 1 , 10]
[1,2,11]</syntaxhighlight>

=={{header|Jsish}}==
<syntaxhighlight lang="javascript">/* Apply callback, in Jsish using array.map() */
;[1, 2, 3, 4, 5].map(function(v,i,a) { return v * v; });

/*
=!EXPECTSTART!=
[1, 2, 3, 4, 5].map(function(v,i,a) { return v * v; }) ==> [ 1, 4, 9, 16, 25 ]
=!EXPECTEND!=
*/</syntaxhighlight>

{{out}}
<pre>prompt$ jsish -u applyCallback.jsi
[PASS] applyCallback.jsi</pre>

=={{header|Julia}}==
{{works with|Julia|0.6}}
<syntaxhighlight lang="julia">numbers = [1, 3, 5, 7]

@show [n ^ 2 for n in numbers]                  # list comprehension
square(x) = x ^ 2; @show map(square, numbers)   # functional form
@show map(x -> x ^ 2, numbers)                  # functional form with anonymous function
@show [n * n for n in numbers]    				# no need for a function,
@show numbers .* numbers                        # element-wise operation
@show numbers .^ 2                              # includes .+, .-, ./, comparison, and bitwise operations as well</syntaxhighlight>

=={{header|Kotlin}}==
<syntaxhighlight lang="scala">fun main(args: Array<String>) {
    val array = arrayOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)  // build
    val function = { i: Int -> i * i } // function to apply
    val list = array.map { function(it) } // process each item
    println(list) // print results
}</syntaxhighlight>
{{out}}
<pre>[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]</pre>

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

( 1 2 3 4 ) [dup *] map

pstack

" " input</syntaxhighlight>
{{out}}
<pre>((1, 4, 9, 16))</pre>

=={{header|Lambdatalk}}==
<syntaxhighlight lang="scheme">
{A.map {lambda {:x} {* :x :x}} {A.new 1 2 3 4 5 6 7 8 9 10}}
-> [1,4,9,16,25,36,49,64,81,100]
</syntaxhighlight>

=={{header|Lang}}==
<syntaxhighlight lang="lang">
&arr = fn.arrayGenerateFrom(fn.inc, 10)
fn.println(&arr)
fn.arrayMap(&arr, fn.combC(fn.pow, 2))
fn.println(&arr)
</syntaxhighlight>
{{out}}
<pre>
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
</pre>

=={{header|Lang5}}==
<syntaxhighlight lang="lang5">: square(*)  dup * ;
[1 2 3 4 5] square        . "\n" .
[1 2 3 4 5] 'square apply . "\n" .</syntaxhighlight>

=={{header|langur}}==
<syntaxhighlight lang="langur">writeln map fn{^2}, 1..10</syntaxhighlight>

{{out}}
<pre>[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]</pre>

=={{header|Lasso}}==
<syntaxhighlight lang="lasso">define cube(n::integer) => #n*#n*#n

local(
	mynumbers = array(1, 2, 3, 4, 5),
	mycube = array
)

#mynumbers -> foreach => {
	#mycube -> insert(cube(#1))
}

#mycube</syntaxhighlight>
-> array(1, 8, 27, 64, 125)

=={{header|Lisaac}}==
<syntaxhighlight lang="lisaac">+ a : ARRAY(INTEGER);
+ b : {INTEGER;};

a := ARRAY(INTEGER).create 1 to 3;
1.to 3 do { i : INTEGER;
  a.put i to i;
};

b := { arg : INTEGER;
  (arg * arg).print;
  '\n'.print;
};

a.foreach b;</syntaxhighlight>

=={{header|Logo}}==
<syntaxhighlight lang="logo">to square :x
  output :x * :x
end
show map "square [1 2 3 4 5]  ; [1 4 9 16 25]
show map [? * ?] [1 2 3 4 5]  ; [1 4 9 16 25]
foreach [1 2 3 4 5] [print square ?]  ; 1 4 9 16 25, one per line</syntaxhighlight>

=={{header|Lua}}==

Say we have an array:
<syntaxhighlight lang="lua">myArray = {1, 2, 3, 4, 5}</syntaxhighlight>
A map function for this would be
<syntaxhighlight lang="lua">map = function(f, data)
   local result = {}
   for k,v in ipairs(data) do
      result[k] = f(v)
   end
   return result
end</syntaxhighlight>
Together with our array and a square function this yields:
<syntaxhighlight lang="lua">myFunc = function(x) return x*x end

print(unpack( map(myFunc, myArray) ))
--> 1   4   9   16  25</syntaxhighlight>
If you used pairs() instead of ipairs(), this would even work on a hash table in general.
However, remember that hash table do not have an implicit ordering on their elements, like arrays do,
so pairs() is not guaranteed to return the elements in the same order as ipairs()

=={{header|M2000 Interpreter}}==
<syntaxhighlight lang="m2000 interpreter">
a=(1,2,3,4,5)
b=lambda->{
	push number**2	
}
Print a#map(b) ' 1 4 9 16 25
Print a#map(b, b)  ' 1 16 81 256 625
b=lambda (z) ->{
	=lambda z ->{
		push number**z	
	}	
}
Print a#map(b(2)) ' 1 4 9 16 25
Print a#map(b(3)) ' 1 8 27 64 125

\\ second example
a=(1,2,3,4,5)
class s {sum=0}
\\ s is a pointer to an instance of s()
s->s()
c=lambda s -> {
	push number+number
	s=>sum=stackitem()  ' peek the value from stack
}
\\ c passed by value to fold(), but has a pointer to s
Print a#fold(c, 100)=115
Print s=>sum=115

</syntaxhighlight>

=={{header|M4}}==
<syntaxhighlight lang="m4">define(`foreach', `pushdef(`$1')_foreach($@)popdef(`$1')')dnl
define(`_arg1', `$1')dnl
define(`_foreach', `ifelse(`$2', `()', `',
   `define(`$1', _arg1$2)$3`'$0(`$1', (shift$2), `$3')')')dnl
dnl
define(`apply',`foreach(`x',$1,`$2(x)')')dnl
dnl
define(`z',`eval(`$1*2') ')dnl
apply(`(1,2,3)',`z')</syntaxhighlight>

{{Out}}
<pre>
2 4 6
</pre>

=={{header|Maple}}==
For lists and sets, which in Maple are immutable, a new object is returned.  
Either the built-in procedure map, or the short syntax of a trailing tilde (~) on the applied operator may be used.
<syntaxhighlight lang="maple">
> map( sqrt, [ 1.1, 3.2, 5.7 ] );
                [1.048808848, 1.788854382, 2.387467277]

> map( x -> x + 1, { 1, 3, 5 } );
                               {2, 4, 6}

> sqrt~( [ 1.1, 3.2, 5.7 ] );
                [1.048808848, 1.788854382, 2.387467277]

> (x -> x + 1)~( { 1, 3, 5 } );
                               {2, 4, 6}
</syntaxhighlight>
For Arrays (Vectors, Matrices, etc.) both map and trailing tilde also work, and by default create a new object, leaving the input Array unchanged.
<syntaxhighlight lang="maple">
> a := Array( [ 1.1, 3.2, 5.7 ] );
                          a := [1.1, 3.2, 5.7]

> sqrt~( a );
                [1.048808848, 1.788854382, 2.387467277]

> a;
                            [1.1, 3.2, 5.7]

> map( sqrt, a );
                [1.048808848, 1.788854382, 2.387467277]

> a;
                            [1.1, 3.2, 5.7]
</syntaxhighlight>
However, since these are mutable data structures in Maple, it is possible to use map to modify its input according to the applied procedure.
<syntaxhighlight lang="maple">
> map[inplace]( sqrt, a );
                [1.048808848, 1.788854382, 2.387467277]

> a;
                [1.048808848, 1.788854382, 2.387467277]
</syntaxhighlight>
The Array a has been modified.

It is also possible to pass additional arguments to the mapped procedure.
<syntaxhighlight lang="maple">
> map( `+`, [ 1, 2, 3 ], 3 );
                               [4, 5, 6]
</syntaxhighlight>
Passing additional arguments *before* the arguments from the mapped data structure is achieved using map2, or the more general map[n] procedure.
<syntaxhighlight lang="maple">
> map2( `-`, 5, [ 1, 2, 3 ] );
                               [4, 3, 2]

> map[2]( `/`, 5, [ 1, 2, 3 ] );
                             [5, 5/2, 5/3]
</syntaxhighlight>

=={{header|Mathematica}}//{{header|Wolfram Language}}==
<syntaxhighlight lang="mathematica">(#*#)& /@ {1, 2, 3, 4}
Map[Function[#*#], {1, 2, 3, 4}]
Map[((#*#)&,{1,2,3,4}]
Map[Function[w,w*w],{1,2,3,4}]</syntaxhighlight>

=={{header|MATLAB}}==
There are two types of arrays in MATLAB: arrays and cell arrays. MATLAB includes two functions, one for each of these data types, that accomplish the specification for this task. For arrays, we use "arrayfun()"; for cell arrays we use "cellfun()".<br />
Example:
For both of these function the first argument is a function handle for the function we would like to apply to each element. The second argument is the array whose elements are modified by the function. The function can be any function, including user defined functions.
<syntaxhighlight lang="matlab">>> array = [1 2 3 4 5]

array =

     1     2     3     4     5

>> arrayfun(@sin,array)

ans =

  Columns 1 through 4

   0.841470984807897   0.909297426825682   0.141120008059867  -0.756802495307928

  Column 5

  -0.958924274663138

>> cellarray = {1,2,3,4,5}

cellarray = 

    [1]    [2]    [3]    [4]    [5]

>> cellfun(@tan,cellarray)

ans =

  Columns 1 through 4

   1.557407724654902  -2.185039863261519  -0.142546543074278   1.157821282349578

  Column 5

  -3.380515006246586</syntaxhighlight>

=={{header|Maxima}}==
<syntaxhighlight lang="maxima">/* for lists or sets */

map(sin, [1, 2, 3, 4]);
map(sin, {1, 2, 3, 4});

/* for matrices */

matrixmap(sin, matrix([1, 2], [2, 4]));</syntaxhighlight>

=={{header|min}}==
{{works with|min|0.19.3}}
<syntaxhighlight lang="min">(1 2 3 4 5) (sqrt puts) foreach   ; print each square root
(1 2 3 4 5) 'sqrt map             ; collect return values</syntaxhighlight>

=={{header|Modula-3}}==
<syntaxhighlight lang="modula3">MODULE Callback EXPORTS Main;

IMPORT IO, Fmt;

TYPE CallBack = PROCEDURE (a: CARDINAL; b: INTEGER);
     Values = REF ARRAY OF INTEGER;

VAR sample := ARRAY [1..5] OF INTEGER {5, 4, 3, 2, 1};
    callback := Display;

PROCEDURE Display(loc: CARDINAL; val: INTEGER) =
  BEGIN
    IO.Put("array[" & Fmt.Int(loc) & "] = " & Fmt.Int(val * val) & "\n");
  END Display;

PROCEDURE Map(VAR values: ARRAY OF INTEGER; size: CARDINAL; worker: CallBack) =
  VAR lvalues := NEW(Values, size);
  BEGIN
    FOR i := FIRST(lvalues^) TO LAST(lvalues^) DO
      worker(i, values[i]);
    END;
  END Map;

BEGIN
  Map(sample, NUMBER(sample), callback);
END Callback.</syntaxhighlight>

=={{header|Nanoquery}}==
<syntaxhighlight lang="nanoquery">// create a list of numbers 1-10
numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 
// display the list as it is
println numbers
 
// square each element in the list
for i in range(1, len(numbers) - 1)
	numbers[i] = numbers[i] * numbers[i]
end
 
// display the squared list
println numbers</syntaxhighlight>
{{out}}
<pre>[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]</pre>

=={{header|Nemerle}}==
The <tt>Nemerle.Collections</tt> namespace defines the methods <tt>Iter()</tt> (if the function applied is <tt>void</tt>) and <tt>Map()</tt> (if the function applied returns a value).
<syntaxhighlight lang="nemerle">def seg = array[1, 2, 3, 5, 8, 13];
def squares = seq.Map(x => x*x);</syntaxhighlight>

=={{header|NetLogo}}==
<syntaxhighlight lang="netlogo">
;; NetLogo “anonymous procedures”
;; stored in a variable, just to show it can be done.
let callback [ [ x ] x * x ]
show (map callback [ 1 2 3 4 5 ])
</syntaxhighlight>

=={{header|NewLISP}}==

<syntaxhighlight lang="newlisp">> (map (fn (x) (* x x)) '(1 2 3 4))
(1 4 9 16)
</syntaxhighlight>

=={{header|NGS}}==
<syntaxhighlight lang="ngs">{
	[1, 2, 3, 4, 5].map(F(x) x*x)
}</syntaxhighlight>

=={{header|Nial}}==

<syntaxhighlight lang="nial">each (* [first, first] ) 1 2 3 4
=1 4 9 16</syntaxhighlight>

=={{header|Nim}}==

<syntaxhighlight lang="nim">
from std/sequtils import apply
let arr = @[1,2,3,4]
arr.apply proc(some: int) = echo(some, " squared = ", some*some)</syntaxhighlight>

{{Out}}
  1 squared = 1
  2 squared = 4
  3 squared = 9
  4 squared = 16

=={{header|Nutt}}==
<syntaxhighlight lang="Nutt">
module main
imports native.io.output.say

operator |> (arr:Array,f:Procedure):Array==>{f(x) of x |-> arr}

say({0,1,2,3,4,5}|>a==>a+2)//|{2,3,4,5,6,7}

end
</syntaxhighlight>


=={{header|Oberon-2}}==
{{Works with|oo2x}}
<syntaxhighlight lang="oberon2">
MODULE ApplyCallBack;
IMPORT
  Out := NPCT:Console;

TYPE
  Fun = PROCEDURE (x: LONGINT): LONGINT;
  Ptr2Ary = POINTER TO ARRAY OF LONGINT;

VAR
  a: ARRAY 5 OF LONGINT;
  x: ARRAY 3 OF LONGINT;
  r: Ptr2Ary;

  PROCEDURE Min(x,y: LONGINT): LONGINT;
  BEGIN
    IF x <= y THEN RETURN x ELSE RETURN y END;
  END Min;

  PROCEDURE Init(VAR a: ARRAY OF LONGINT);
  BEGIN
    a[0] := 0;
    a[1] := 1;
    a[2] := 2;
    a[3] := 3;
    a[4] := 4;
  END Init;

  PROCEDURE Fun1(x: LONGINT): LONGINT;
  BEGIN
    RETURN x * 2
  END Fun1;

  PROCEDURE Fun2(x: LONGINT): LONGINT;
  BEGIN
    RETURN x DIV 2;
  END Fun2;

  PROCEDURE Fun3(x: LONGINT): LONGINT;
  BEGIN
    RETURN x + 3;
  END Fun3;
  
  PROCEDURE Map(F: Fun; VAR x: ARRAY OF LONGINT);
  VAR
    i: LONGINT;
  BEGIN 
    FOR i := 0 TO LEN(x) - 1 DO
      x[i] := F(x[i])
    END
  END Map;

  PROCEDURE Map2(F: Fun; a: ARRAY OF LONGINT; VAR r: ARRAY OF LONGINT);
  VAR
    i,l: LONGINT;
  BEGIN
    l := Min(LEN(a),LEN(x));
    FOR i := 0 TO l - 1 DO 
      r[i] := F(a[i])
    END
  END Map2;

  PROCEDURE Map3(F: Fun; a: ARRAY OF LONGINT): Ptr2Ary;
  VAR
    r: Ptr2Ary;
    i: LONGINT;
  BEGIN
    NEW(r,LEN(a));
    FOR i := 0 TO LEN(a) - 1 DO
      r[i] := F(a[i]);
    END;
    RETURN r
  END Map3;

  PROCEDURE Show(a: ARRAY OF LONGINT);
  VAR
    i: LONGINT;
  BEGIN
    FOR i := 0 TO LEN(a) - 1 DO
      Out.Int(a[i],4)
    END;
    Out.Ln
  END Show;
  
BEGIN
  Init(a);Map(Fun1,a);Show(a);
  Init(a);Map2(Fun2,a,x);Show(x);
  Init(a);r := Map3(Fun3,a);Show(r^);
END ApplyCallBack.
</syntaxhighlight>
{{Out}}
<pre>
   0   2   4   6   8
   0   0   1
   3   4   5   6   7
</pre>

=={{header|Objeck}}==
<syntaxhighlight lang="objeck">
use Structure;

bundle Default {
  class Test {
    function : Main(args : String[]) ~ Nil {
      Run();
    }

    function : native : Run() ~ Nil {
      values := IntVector->New([1, 2, 3, 4, 5]);
      squares := values->Apply(Square(Int) ~ Int);
      each(i : squares) {
        squares->Get(i)->PrintLine();
      };
    }
    
    function : Square(value : Int) ~ Int {
      return value * value;
    }
  }
}
</syntaxhighlight>

=={{header|OCaml}}==
This function is part of the standard library:

<syntaxhighlight lang="ocaml">Array.map</syntaxhighlight>

Usage example:
<syntaxhighlight lang="ocaml">let square x = x * x;;
let values = Array.init 10 ((+) 1);;
Array.map square values;;</syntaxhighlight>

Or with lists (which are more typical in OCaml):
<syntaxhighlight lang="ocaml">let values = [1;2;3;4;5;6;7;8;9;10];;
List.map square values;;</syntaxhighlight>

Use <tt>iter</tt> if the applied function does not return a value.

<syntaxhighlight lang="ocaml">Array.iter (fun x -> Printf.printf "%d" x) [|1; 2; 3; 4; 5|];;</syntaxhighlight>
<syntaxhighlight lang="ocaml">List.iter (fun x -> Printf.printf "%d" x) [1; 2; 3; 4; 5];;</syntaxhighlight>

with partial application we can also write:

<syntaxhighlight lang="ocaml">Array.iter (Printf.printf "%d") [|1; 2; 3; 4; 5|];;</syntaxhighlight>
<syntaxhighlight lang="ocaml">List.iter (Printf.printf "%d") [1; 2; 3; 4; 5];;</syntaxhighlight>

=={{header|Octave}}==

Almost all the built-in can operate on each element of a vector or matrix; e.g. sin([pi/2, pi, 2*pi]) computes the function sin on pi/2, pi and 2*pi (returning a vector). If a function does not accept vectors/matrices as arguments, the <tt>arrayfun</tt> can be used.

<syntaxhighlight lang="octave">function e = f(x, y)
  e = x^2 + exp(-1/(y+1));
endfunction

% f([2,3], [1,4]) gives and error, but
arrayfun(@f, [2, 3], [1,4])
% works</syntaxhighlight>

(The function <tt>f</tt> can be rewritten so that it can accept vectors as argument simply changing operators to their dot ''relatives'': <code>e = x.^2 + exp(-1 ./ (y.+1))</code>)

=={{header|Odin}}==

<syntaxhighlight lang="odin">package main

import "core:slice"
import "core:fmt"

squared :: proc(x: int) -> int {
  return x * x
}

main :: proc() {
  arr := []int{1, 2, 3, 4, 5}
  res := slice.mapper(arr, squared)

  fmt.println(res)  // prints: [1, 4, 9, 16, 25]
}</syntaxhighlight>

=={{header|Oforth}}==
apply allows to perform a function on all elements of a list : 
<syntaxhighlight lang="oforth">0 #+ [ 1, 2, 3, 4, 5 ] apply</syntaxhighlight>

map regroups all results into a new list : 
<syntaxhighlight lang="oforth">#sq [ 1, 2, 3, 4, 5 ] map</syntaxhighlight>

=={{header|Ol}}==
Apply custom callback (lambda) to every element of list.
<syntaxhighlight lang="scheme">
(for-each
   (lambda (element)
      (display element))
   '(1 2 3 4 5))
; ==> 12345
</syntaxhighlight>

=={{header|ooRexx}}==
ooRexx doesn't directly support callbacks on array items, but this is pretty easy to implement using Routine objects. 
<syntaxhighlight lang="oorexx">start = .array~of("Rick", "Mike", "David", "Mark")
new = map(start, .routines~reversit)
call map new, .routines~sayit


-- a function to perform an iterated callback over an array
-- using the provided function.  Returns an array containing
-- each function result
::routine map
  use strict arg array, function
  resultArray = .array~new(array~items)
  do item over array
     resultArray~append(function~call(item))
  end
  return resultArray

::routine reversit
  use arg string
  return string~reverse

::routine sayit
  use arg string
  say string
  return .true   -- called as a function, so a result is required</syntaxhighlight>
{{out}}
<pre>kciR
ekiM
divaD
kraM</pre>

=={{header|Order}}==
Both sequences and tuples support the usual map operation seen in many functional languages. Sequences also support <code>8seq_for_each</code>, and a few variations, which returns <code>8nil</code>.
<syntaxhighlight lang="c">#include <order/interpreter.h>

ORDER_PP( 8tuple_map(8fn(8X, 8times(8X, 8X)), 8tuple(1, 2, 3, 4, 5)) )
// -> (1,4,9,16,25)

ORDER_PP( 8seq_map(8fn(8X, 8times(8X, 8X)), 8seq(1, 2, 3, 4, 5)) )
// -> (1)(4)(9)(16)(25)

ORDER_PP( 8seq_for_each(8fn(8X, 8print(8X 8comma)), 8seq(1, 2, 3, 4, 5)) )
// prints 1,2,3,4,5, and returns 8nil</syntaxhighlight>

=={{header|Oz}}==
<syntaxhighlight lang="oz">declare
  fun{Square A}
    A*A
  end

  Lst = [1 2 3 4 5]
  
  %% apply a PROCEDURE to every element
  {ForAll Lst Show}

  %% apply a FUNCTION to every element
  Result = {Map Lst Square}
  {Show Result}</syntaxhighlight>

=={{header|PARI/GP}}==
{{works with|PARI/GP|2.4.2 and above}}
<syntaxhighlight lang="parigp">callback(n)=n+n;
apply(callback, [1,2,3,4,5])</syntaxhighlight>

This should be contrasted with <code>call</code>:
<syntaxhighlight lang="parigp">call(callback, [1,2,3,4,5])</syntaxhighlight>
which is equivalent to <code>callback(1, 2, 3, 4, 5)</code> rather than <code>[callback(1), callback(2), callback(3), callback(4), callback(5)]</code>.

=={{header|Pascal}}==
See [[Apply_a_callback_to_an_array#Delphi | Delphi]]

=={{header|Perl}}==
<syntaxhighlight lang="perl"># create array
my @a = (1, 2, 3, 4, 5);

# create callback function
sub mycallback {
  return 2 * shift;
}

# use array indexing
for (my $i = 0; $i < scalar @a; $i++) {
  print "mycallback($a[$i]) = ", mycallback($a[$i]), "\n";
}

# using foreach
foreach my $x (@a) {
  print "mycallback($x) = ", mycallback($x), "\n";
}

# using map (useful for transforming an array)
my @b = map mycallback($_), @a;                # @b is now (2, 4, 6, 8, 10)

# and the same using an anonymous function
my @c = map { $_ * 2 } @a;                     # @c is now (2, 4, 6, 8, 10)

# use a callback stored in a variable
my $func = \&mycallback;
my @d = map $func->($_), @a;                  # @d is now (2, 4, 6, 8, 10)

# filter an array 
my @e = grep { $_ % 2 == 0 } @a;               # @e is now (2, 4)</syntaxhighlight>

=={{header|Phix}}==
{{libheader|Phix/basics}}
<!--<syntaxhighlight lang="phix">(phixonline)-->
 <span style="color: #7060A8;">requires</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0.8.2"</span><span style="color: #0000FF;">)</span>
  
 <span style="color: #008080;">function</span> <span style="color: #000000;">add1</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">return</span> <span style="color: #000000;">x</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">1</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
  
 <span style="color: #0000FF;">?</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">({</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">},</span><span style="color: #000000;">add1</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
{2,3,4}
</pre>
There are in fact three ways to invoke apply:<br>
The oldest/original, as above, is apply(s,fn), where fn is invoked length(s) times with a single parameter of s[i].<br>
apply(false,fn,s) likewise invokes fn length(s) times, but each time with length(s[i]) parameters.<br>
apply(true,sprintf,{{"%d"},s}), the third way, invokes sprintf length(s) times with two parameters, being "%d" and each s[i].<br>
This last way scans it's third argument looking for a (consistent) longest length to determine how many times to invoke sprintf, <br>
uses the length of it's third argument to determine how many parameters each call will get, and <br>
uses the same value on every call for any atom or length 1 elements, such as that {"%d"}.

=={{header|Phixmonti}}==
<syntaxhighlight lang="phixmonti">/# Rosetta Code problem: http://rosettacode.org/wiki/Apply_a_callback_to_an_array
by Galileo, 05/2022 #/

include ..\Utilitys.pmt

def ++
    1 +
enddef

def square
    dup *
enddef

( 1 2 3 ) dup

getid ++ map swap
getid square map

pstack</syntaxhighlight>
{{out}}
<pre>
[[2, 3, 4], [1, 4, 9]]

=== Press any key to exit ===</pre>

=={{header|PHP}}==
<syntaxhighlight lang="php">function cube($n)
{
   return($n * $n * $n);
}

$a = array(1, 2, 3, 4, 5);
$b = array_map("cube", $a);
print_r($b);</syntaxhighlight>

=={{header|Picat}}==
Picat doesn't support anonymous (lambda) functions so the function must be defined in the program to be used by - say - map/2.
There are - however - quite a few ways without proper lambdas, using map/2, apply/2, or list comprehensions.
<syntaxhighlight lang="picat">go => 
   L = 1..10,

   % Using map/2 in different ways
   println(L.map(fun)), 
   println(map(L,fun)),   
   println(map(fun,L)),

   % List comprehensions
   println([fun(I) : I in L]),

   % Using apply/2
   println([apply(fun,I) : I in L]),

   % And using list comprehension with the function directly.
   println([I*I : I in L]),
   nl.

% Some function
fun(X) = X*X.
</syntaxhighlight>

{{trans|Prolog}}
This variant is inspired by the Prolog solution (using assert/1 to define a predicate) and shows the integration with Picat's underlying B-Prolog engine.

Picat does not support assert/1 directly, so one have to do the assert/1 in the bp module space (the module/space for the B-Prolog engine). To call the defined predicate, one must prepend the predicate name with "bp.".

Note that fun2/2 is not a function so map/2 or apply/2 cannot be used here.
<syntaxhighlight lang="picat">go2 =>
   L = 1..10,

   % Define the predicate _in the bp space_.
   bp.assert( $(fun2(X,Y) :- Y is X*X) ),

   % Use bp.fun2 to call the function.
   println([B : A in L, bp.fun2(A,B)]),
   nl.
</syntaxhighlight>

Using this technique one can do quite much "real" Prolog stuff even though Picat doesn't support it directly. However, one should be careful with this approach since it can sometimes be confusing and it doesn't work in all cases.

=={{header|PicoLisp}}==
<syntaxhighlight lang="picolisp">: (mapc println (1 2 3 4 5))  # Print numbers
1
2
3
4
5
-> 5

: (mapcar '((N) (* N N)) (1 2 3 4 5))  # Calculate squares
-> (1 4 9 16 25)

: (mapcar ** (1 2 3 4 5) (2 .))  # Same, using a circular list
-> (1 4 9 16 25)

: (mapcar if '(T NIL T NIL) '(1 2 3 4) '(5 6 7 8))  # Conditional function
-> (1 6 3 8)</syntaxhighlight>

=={{header|Pike}}==
<syntaxhighlight lang="pike">int cube(int n)
{
    return n*n*n;
}

array(int) a = ({ 1,2,3,4,5 });
array(int) b = cube(a[*]);      // automap operator
array(int) c = map(a, cube);    // conventional map function</syntaxhighlight>

=={{header|PL/I}}==
<syntaxhighlight lang="pl/i">   declare x(5) initial (1,3,5,7,8);
   x = sqrt(x);
   x = sin(x);</syntaxhighlight>

=={{header|PL/SQL}}==
PL/SQL doesn't have callbacks, though we can pass around an object and use its method to simulate one. Further, this callback method can be defined in an abstract class that the mapping function will expect.
<syntaxhighlight lang="plsql">-- Let's create a generic class with one method to be used as an interface:
create or replace
TYPE callback AS OBJECT (
    -- A class needs at least one member even though we don't use it
    -- There's no generic OBJECT type, so let's call it NUMBER
    dummy NUMBER,
    -- Here's our function, and since PL/SQL doesn't have generics,
    -- let's use type NUMBER for our params
    MEMBER FUNCTION exec(n number) RETURN number
) NOT FINAL not instantiable;
/

-- Now let's inherit from that, defining a class with one method. We'll have ours square a number.
-- We can pass this class into any function that takes type callback:
CREATE OR REPLACE TYPE CB_SQUARE under callback (
    OVERRIDING MEMBER FUNCTION exec(n NUMBER) RETURN NUMBER
)
/
CREATE OR REPLACE
TYPE BODY CB_SQUARE AS
    OVERRIDING MEMBER FUNCTION exec(n NUMBER) RETURN NUMBER IS
    BEGIN
        RETURN n * n;
    END exec;
END;
/

-- And a package to hold our test
CREATE OR REPLACE 
PACKAGE PKG_CALLBACK AS 
    myCallback cb_square;
    TYPE intTable IS TABLE OF NUMBER INDEX BY BINARY_INTEGER;
    ints intTable;
    i PLS_INTEGER;
    
    procedure test_callback;
END PKG_CALLBACK;
/

CREATE OR REPLACE PACKAGE BODY PKG_CALLBACK AS
    -- Our generic mapping function that takes a "method" and a collection
    -- Note that it takes the generic callback type 
    -- that doesn't know anything about squaring
    procedure do_callback(myCallback IN callback, ints IN OUT intTable) IS
        i PLS_INTEGER;
        myInt NUMBER;
    begin
        for i in 1 .. ints.count loop
            myInt := ints(i);
            -- PL/SQL call's the child's method
            ints(i) := myCallback.exec(myInt);
        END LOOP;
    end do_callback;

    procedure test_callback IS
    BEGIN
        myCallback := cb_square(null);
        FOR i IN 1..5 LOOP
            ints(i) := i;
        END LOOP;
    
        do_callback(myCallback, ints);
    
        i := ints.FIRST;
        WHILE i IS NOT NULL LOOP
            DBMS_OUTPUT.put_line(ints(i));
            i := ints.next(i);
        END LOOP;
    END test_callback;
END PKG_CALLBACK;
/

BEGIN
  PKG_CALLBACK.TEST_CALLBACK();
END;
/</syntaxhighlight>

=={{header|Pop11}}==

<syntaxhighlight lang="pop11">;;; Define a procedure
define proc(x);
    printf(x*x, '%p,');
enddefine;

;;; Create array
lvars ar = { 1 2 3 4 5};

;;; Apply procedure to array
appdata(ar, proc);</syntaxhighlight>

If one wants to create a new array consisting of transformed values then procedure mapdata may be more convenient.

=={{header|PostScript}}==
The <code>forall</code> operator applies a procedure to each element of an array, a packed array or a string.
<syntaxhighlight lang="postscript">[1 2 3 4 5] { dup mul = } forall</syntaxhighlight>
In this case the respective square numbers for the elements are printed.

To create a new array from the results above code can simply be wrapped in <code>[]</code>:
<syntaxhighlight lang="postscript">[ [1 2 3 4 5] { dup mul } forall ]</syntaxhighlight>

{{libheader|initlib}}
<syntaxhighlight lang="postscript">
[1 2 3 4 5] {dup *} map
</syntaxhighlight>

=={{header|PowerShell}}==
This can be done in PowerShell with the <code>ForEach-Object</code> cmdlet which applies a scriptblock to each element of an array:
<syntaxhighlight lang="powershell">1..5 | ForEach-Object { $_ * $_ }</syntaxhighlight>
To recreate a ''map'' function, found in other languages the same method applies:
<syntaxhighlight lang="powershell">function map ([array] $a, [scriptblock] $s) {
    $a | ForEach-Object $s
}
map (1..5) { $_ * $_ }</syntaxhighlight>

=={{header|Prolog}}==
Prolog doesn't have arrays, but we can do it with lists. This can be done in the console mode. 
<syntaxhighlight lang="prolog"> ?- assert((fun(X, Y) :- Y is 2 * X)).
true.

?- maplist(fun, [1,2,3,4,5], L).
L = [2,4,6,8,10].
</syntaxhighlight>

=={{header|PureBasic}}==
<syntaxhighlight lang="purebasic">Procedure Cube(Array param.i(1))
    Protected n.i
    For n = 0 To ArraySize(param())
        Debug Str(param(n)) + "^3 = " + Str(param(n) * param(n) * param(n))
    Next 
EndProcedure 

Dim AnArray.i(4)

For n = 0 To ArraySize(AnArray()) 
    AnArray(n) = Random(99)
Next 

Cube(AnArray()) </syntaxhighlight>

=={{header|Python}}==
<syntaxhighlight lang="python">def square(n):
    return n * n
  
numbers = [1, 3, 5, 7]

squares1 = [square(n) for n in numbers]     # list comprehension

squares2a = map(square, numbers)            # functional form

squares2b = map(lambda x: x*x, numbers)     # functional form with `lambda`

squares3 = [n * n for n in numbers]         # no need for a function,
                                            # anonymous or otherwise

isquares1 = (n * n for n in numbers)        # iterator, lazy

import itertools
isquares2 = itertools.imap(square, numbers) # iterator, lazy</syntaxhighlight>
To print squares of integers in the range from 0 to 9, type:
<syntaxhighlight lang="python">print " ".join(str(n * n) for n in range(10))</syntaxhighlight>
Or:
<syntaxhighlight lang="python">print " ".join(map(str, map(square, range(10))))</syntaxhighlight>
Result:
<syntaxhighlight lang="python">0 1 4 9 16 25 36 49 64 81</syntaxhighlight>

=={{header|QB64}}==
<syntaxhighlight lang="qb64">
'Task
'Take a combined set of elements and apply a function to each element.
'UDT
Type Friend
    Names As String * 8
    Surnames As String * 8
    Age As Integer
End Type

Dim Friends(1 To 6) As Friend
Restore
FillArray
SearchForAdult Friends(), LBound(friends), UBound(friends)

End

Data "John","Beoz",13,"Will","Strange",22
Data "Arthur","Boile",16,"Peter","Smith",21
Data "Tom","Parker",14,"Tim","Wesson",24

Sub FillArray
    Shared Friends() As Friend
    Dim indeX As Integer
    For indeX = LBound(friends) To UBound(friends) Step 1
        Read Friends(indeX).Names, Friends(indeX).Surnames, Friends(indeX).Age
    Next
End Sub

Sub SearchForAdult (F() As Friend, Min As Integer, Max As Integer)
    Dim Index As Integer
    Print "Friends with more than 18 years old"
    For Index = Min To Max Step 1
        If F(Index).Age > 18 Then Print F(Index).Names; " "; F(Index).Surnames; " "; F(Index).Age
    Next Index
End Sub

</syntaxhighlight>

=={{header|Quackery}}==

As a dialogue in the Quackery shell (REPL), applying the word <code>cubed</code> to the nest <code>[ 1 2 3 4 5 6 7 8 9 10 ]</code>, first treating the nest as a list, then as an array.

<syntaxhighlight lang="quackery">/O> [ 3 ** ] is cubed ( n --> n )
... 

Stack empty.

/O> ' [ 1 2 3 4 5 6 7 8 9 10 ]
... [] swap witheach 
...   [ cubed join ]
... 

Stack: [ 1 8 27 64 125 216 343 512 729 1000 ] 

/O> drop
... 

Stack empty.

/O> ' [ 1 2 3 4 5 6 7 8 9 10 ]
... dup witheach
...   [ cubed swap i^ poke ]
... 

Stack: [ 1 8 27 64 125 216 343 512 729 1000 ]</syntaxhighlight>

=={{header|R}}==
Many functions can take advantage of implicit vectorisation, e.g.
<syntaxhighlight lang="r">cube <- function(x) x*x*x
elements <- 1:5
cubes <- cube(elements)</syntaxhighlight>
Explicit looping over array elements is also possible.
<syntaxhighlight lang="r">cubes <- numeric(5)
for(i in seq_along(cubes))
{
   cubes[i] <- cube(elements[i])
}</syntaxhighlight>
Loop syntax can often simplified using the [http://stat.ethz.ch/R-manual/R-patched/library/base/html/apply.html *apply] family of functions.
<syntaxhighlight lang="r">elements2 <- list(1,2,3,4,5)
cubes <- sapply(elements2, cube)</syntaxhighlight>
In each case above, the value of 'cubes' is 
 1   8  27  64 125

=={{header|Racket}}==

<syntaxhighlight lang="racket">
#lang racket

;; using the `for/vector' comprehension form
(for/vector ([i #(1 2 3 4 5)]) (sqr i))

;; the usual functional `map'
(vector-map sqr #(1 2 3 4 5))
</syntaxhighlight>

=={{header|Raku}}==
(formerly Perl 6)
{{works with|Rakudo|2015.10-11}}

<syntaxhighlight lang="raku" line>sub function { 2 * $^x + 3 };
my @array = 1 .. 5;

# via map function
.say for map &function, @array;

# via map method
.say for @array.map(&function);

# via for loop
for @array {
    say function($_);
}

# via the "hyper" metaoperator and method indirection
say @array».&function;

# we neither need a variable for the array nor for the function
say [1,2,3]>>.&({ $^x + 1});
</syntaxhighlight>

=={{header|Raven}}==
<syntaxhighlight lang="raven"># To print the squared elements
[1 2 3 4 5] each dup * print</syntaxhighlight>

<syntaxhighlight lang="raven"># To obtain a new array
group [1 2 3 4 5] each
  dup *
list</syntaxhighlight>

=={{header|REBOL}}==
<syntaxhighlight lang="rebol">REBOL [
    Title: "Array Callback"
    URL: http://rosettacode.org/wiki/Apply_a_callback_to_an_Array
]

map: func [
	"Apply a function across an array."
	f [native! function!] "Function to apply to each element of array."
	a [block!] "Array to process."
	/local x
][x: copy []  forall a [append x do [f a/1]]  x]

square: func [x][x * x]

; Tests:

assert: func [code][print [either do code ["  ok"]["FAIL"]  mold code]]

print "Simple loop, modify in place:"
assert [[1 100 81] = (a: [1 10 9]  forall a [a/1: square a/1]  a)]

print [crlf "Functional style with 'map':"]
assert [[4 16 36] = map :square [2 4 6]]

print [crlf "Applying native function with 'map':"]
assert [[2 4 6] = map :square-root [4 16 36]]</syntaxhighlight>

{{Out}}
<pre>Simple loop, modify in place:
  ok [[1 100 81] = (a: [1 100 81] forall a [a/1: square a/1] a)]

Functional style with 'map':
  ok [[4 16 36] = map :square [2 4 6]]

Applying native function with 'map':
  ok [[2 4 6] = map :square-root [4 16 36]]</pre>

=={{header|Retro}}==

Retro provides a variety of array words. Using these to multiply each value in an array by 10 and display the results:

<syntaxhighlight lang="retro">{ #1 #2 #3 #4 #5 } [ #10 * ] a:map [ n:put sp ] a:for-each</syntaxhighlight>

=={{header|REXX}}==
<syntaxhighlight lang="rexx">/*REXX program applies a  callback  to an array  (using factorials for a demonstration).*/
numeric digits 100                               /*be able to display some huge numbers.*/
parse arg # .                                    /*obtain an optional value from the CL.*/
a.=                                              /*initialize the array  A  to all nulls*/
if #=='' | #==","  then #= 12                    /*Not assigned?  Then use default value*/
                        do j=0  to #;   a.j= j   /*assign the integer   J  ───►   A.j   */
                        end   /*j*/              /*array  A  will have N values: 0 ──► #*/

call listA   'before callback'                   /*display  A  array before the callback*/
say                                              /*display a blank line for readability.*/
say '      ··· applying callback to array A ···' /*display what is about to happen to B.*/
say                                              /*display a blank line for readability.*/
call bangit  'a'                                 /*factorialize (the values) of A array.*/
                                                 /*    store the results  ───►  array B.*/
call listA   ' after callback'                   /*display  A  array after the callback.*/
exit 0                                           /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
bangit:   do v=0;  $= value(arg(1)'.'v);  if $=='' then return  /*No value?  Then return*/
          call value arg(1)'.'v, fact($)         /*assign a value (a factorial) to array*/
          end    /*i*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
fact:   procedure; arg x;   != 1;         do f=2  to x;  != !*f;  end; /*f*/;     return !
listA:    do k=0  while a.k\=='';  say arg(1)  'a.'k"="  a.k;     end  /*k*/;     return</syntaxhighlight>
{{out|output|text=&nbsp; when using the default input:}}
<pre>
before callback a.0= 0
before callback a.1= 1
before callback a.2= 2
before callback a.3= 3
before callback a.4= 4
before callback a.5= 5
before callback a.6= 6
before callback a.7= 7
before callback a.8= 8
before callback a.9= 9
before callback a.10= 10
before callback a.11= 11
before callback a.12= 12

      ··· applying callback to array A ···

 after callback a.0= 1
 after callback a.1= 1
 after callback a.2= 2
 after callback a.3= 6
 after callback a.4= 24
 after callback a.5= 120
 after callback a.6= 720
 after callback a.7= 5040
 after callback a.8= 40320
 after callback a.9= 362880
 after callback a.10= 3628800
 after callback a.11= 39916800
 after callback a.12= 479001600
</pre>

=={{header|Ring}}==
<syntaxhighlight lang="ring">
for x in [1,2,3,4,5]
    x = x*x
next
</syntaxhighlight>

=={{header|RLaB}}==
RLaB has two type of arrays: 'standard' or 1-dimensional, that can be a row-
or a column-vectory; and, 'associative' which are called lists.
For standard array its entry identifier (index) is an integer in
range 1:N where N is the size of the array.
For associative array its entry identifier is a string consisting of printable
ASCII characters.

All scalar mathematical functions are 'matrix-optimized' meaning that if the argument
to a function is a matrix, then the return value of the function is a matrix of the
same size as the input argument, where the function is applied to the individual entries
of the matrix.
Consider an example:

<syntaxhighlight lang="rlab">
>> x = rand(2,4)
 0.707213207   0.275298961   0.396757763   0.232312312
 0.215619868   0.207078017   0.565700032   0.666090571
>> sin(x)
 0.649717845   0.271834652   0.386430003   0.230228332
 0.213952984   0.205601224   0.536006923   0.617916954
</syntaxhighlight>

This can be done on entry-by-entry basis, but one has to keep in mind that the
'for' or 'while' loops are slow in interpreted languages, and RLaB is no exception.

<syntaxhighlight lang="rlab">
x = rand(2,4);
y = zeros(2,4);
for (i in 1:2)
{
  for (j in 1:4)
  {
    y[i;j] = sin( x[i;j] );
  }
}
</syntaxhighlight>


The functions can take lists as arguments, but then it has to be specified within the body
of the function what to do with the list elements. Given a list call it 'x' there is a RLaB 
function 'members' which returns a string vector with the names of the elements of the list.

<syntaxhighlight lang="rlab">
x = <<>>;
for (i in 1:9)
{
  x.[i] = rand();
}

y = <<>>;
for (i in members(x))
{
  y.[i] = sin( x.[i] );
}
</syntaxhighlight>

=={{header|RPL}}==
{{works with|Halcyon Calc|4.2.7}}
 ≪ → array func 
   ≪ array 0 CON 
      1 array SIZE FOR j 
         j array j GET func EVAL PUT 
      NEXT 
 ≫  ≫ 
 ´MAP’ STO

 [1,2,3,4,5,6,7,8,9] ≪ SQ ≫ MAP
{{out}}
<pre>
1: [ 1 4 9 16 25 36 49 64 81 ]
</pre>

=={{header|Ruby}}==
You could use a traditional "for i in arr" approach like below:
<syntaxhighlight lang="ruby">for i in [1,2,3,4,5] do
   puts i**2
end</syntaxhighlight>

Or you could  the more preferred ruby way of an iterator (which is borrowed from SmallTalk)
<syntaxhighlight lang="ruby">[1,2,3,4,5].each{ |i| puts i**2 }</syntaxhighlight>

To create a new array of each value squared
<syntaxhighlight lang="ruby">[1,2,3,4,5].map{ |i| i**2 }</syntaxhighlight>

=={{header|Rust}}==

<syntaxhighlight lang="rust">fn echo(n: &i32) {
    println!("{}", n);
}

fn main() {
    let a: [i32; 5];
    a = [1, 2, 3, 4, 5];
    let _: Vec<_> = a.into_iter().map(echo).collect();
}</syntaxhighlight>

=={{header|Salmon}}==

These examples apply the square function to a list of the numbers from 0 through 9 to produce a new list of their squares, then iterate over the resulting list and print the squares.

<syntaxhighlight lang="salmon">function apply(list, ageless to_apply)
  (comprehend(x; list) (to_apply(x)));

function square(x) (x*x);

iterate(x; apply([0...9], square))
    x!;</syntaxhighlight>

With short identifiers:

<syntaxhighlight lang="salmon">include "short.salm";

fun apply(list, ageless to_apply)
  (comp(x; list) (to_apply(x)));

fun square(x) (x*x);

iter(x; apply([0...9], square))
    x!;</syntaxhighlight>

With the numbers given as a list of individual elements:

<syntaxhighlight lang="salmon">function apply(list, to_apply)
  (comprehend(x; list) (to_apply(x)));

function square(x) (x*x);

iterate(x; apply([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], square))
    x!;</syntaxhighlight>

=={{header|Sather}}==
<syntaxhighlight lang="sather">class MAIN is
  do_something(i:INT):INT is
    return i * i;
  end;

  main is
    a:ARRAY{INT} := |1, 2, 3, 4, 5|;
    -- we use an anonymous closure to apply our do_something "callback"
    a.map(bind(do_something(_)));
    loop #OUT + a.elt! + "\n"; end;
  end;
end;</syntaxhighlight>

=={{header|Scala}}==
<syntaxhighlight lang="scala">val l = List(1,2,3,4)
l.foreach {i => println(i)}</syntaxhighlight>

When the argument appears only once -as here, i appears only one in println(i) - it may be shortened to
<syntaxhighlight lang="scala">l.foreach(println(_))</syntaxhighlight>
Same for an array
<syntaxhighlight lang="scala">val a = Array(1,2,3,4)
a.foreach {i => println(i)}
a.foreach(println(_))  '' // same as previous line''</syntaxhighlight>

Or for an externally defined function:
<syntaxhighlight lang="scala">def doSomething(in: int) = {println("Doing something with "+in)}
l.foreach(doSomething)</syntaxhighlight>

There is also a ''for'' syntax, which is internally rewritten to call foreach. A foreach method must be defined on ''a''
<syntaxhighlight lang="scala">for(val i <- a) println(i)</syntaxhighlight>

It is also possible to apply a function on each item of an list to get a new list (same on array and most collections)
<syntaxhighlight lang="scala">val squares = l.map{i => i * i} ''//squares is''  List(1,4,9,16)</syntaxhighlight>

Or the equivalent ''for'' syntax, with the additional keyword ''yield'', map is called instead of foreach
<syntaxhighlight lang="scala">val squares = for (val i <- l) yield i * i</syntaxhighlight>

=={{header|Scheme}}==
<syntaxhighlight lang="scheme">(define (square n) (* n n))
(define x #(1 2 3 4 5))
(map square (vector->list x))</syntaxhighlight>

A single-line variation
<syntaxhighlight lang="scheme">(map (lambda (n) (* n n)) '(1 2 3 4 5))</syntaxhighlight>

For completeness, the <tt>map</tt> function (which is R5RS standard) can be coded as follows:
<syntaxhighlight lang="scheme">(define (map f L)
  (if (null? L)
      L
      (cons (f (car L)) (map f (cdr L)))))</syntaxhighlight>

=={{header|SenseTalk}}==
<syntaxhighlight lang="sensetalk">
put each item in [1,2,3,5,9,14,24] squared

put myFunc of each for each item of [1,2,3,5,9,14,24]

to handle myFunc of num
	return 2*num + 1
end myFunc</syntaxhighlight>
Output:
<syntaxhighlight lang="sensetalk">(1,4,9,25,81,196,576)
(3,5,7,11,19,29,49)</syntaxhighlight>

=={{header|Sidef}}==
Defining a callback function:
<syntaxhighlight lang="ruby">func callback(i) { say i**2 }</syntaxhighlight>

The function will get called for each element:
<syntaxhighlight lang="ruby">[1,2,3,4].each(callback)</syntaxhighlight>

Same as above, but with the function inlined:
<syntaxhighlight lang="ruby">[1,2,3,4].each{|i| say i**2 }</syntaxhighlight>

For creating a new array, we can use the Array.map method:
<syntaxhighlight lang="ruby">[1,2,3,4,5].map{|i| i**2 }</syntaxhighlight>

=={{header|Simula}}==
<syntaxhighlight lang="simula">BEGIN

    ! APPLIES A CALLBACK FUNCTION TO AN ARRAY ;
    PROCEDURE APPLY(ARR, FUN);
        REAL ARRAY ARR;
        PROCEDURE FUN IS REAL PROCEDURE FUN(X); REAL X;;
    BEGIN
        INTEGER I;
        FOR I := LOWERBOUND(ARR, 1) STEP 1 UNTIL UPPERBOUND(ARR, 1) DO
            ARR(I) := FUN(ARR(I));
    END APPLY;

    ! CALLBACK ;
    REAL PROCEDURE SQUARE(X); REAL X; SQUARE := X * X;

    REAL ARRAY A(1:5);
    INTEGER I;
    FOR I := 1 STEP 1 UNTIL 5 DO A(I) := I;
    APPLY(A, SQUARE);
    FOR I := 1 STEP 1 UNTIL 5 DO OUTFIX(A(I), 2, 8); OUTIMAGE;

END.</syntaxhighlight>
{{out}}
<pre>
    1.00    4.00    9.00   16.00   25.00
</pre>

=={{header|Slate}}==
<syntaxhighlight lang="slate">#( 1 2 3 4 5 ) collect: [| :n | n * n].</syntaxhighlight>

=={{header|Smalltalk}}==
<syntaxhighlight lang="smalltalk">#( 1 2.0 'three') do: [:each | each displayNl].</syntaxhighlight>
You can tell symbols how to react to the <tt>value:</tt> message, and then write &sup2;:
<syntaxhighlight lang="smalltalk">#( 1 2.0 'three') do: #displayNl.</syntaxhighlight>
2) actually most dialects already have it, and it is trivial to add, if it does not.

There is a huge number of additional enumeration messages implemented in Collection, from which Array inherits. Eg.:
<syntaxhighlight lang="smalltalk">#( 1 2 3 4 5 ) collect: [:n | n * n].</syntaxhighlight>

=={{header|Sparkling}}==
The <tt>foreach</tt> function calls the supplied callback on each element of the (possibly associative) array, passing it each key and the corresponding value:
<syntaxhighlight lang="sparkling">let numbers = { 1, 2, 3, 4 };
foreach(numbers, function(idx, num) {
    print(num);
});</syntaxhighlight>

The <tt>map</tt> function applies the transform to each key-value pair and constructs a new array, of which the keys are the keys of the original array, and the corresponding values are the return values of each call to the transform function:
<syntaxhighlight lang="sparkling">let dict = { "foo": 42, "bar": 13, "baz": 37 };
let doubled = map(dict, function(key, val) {
    return val * 2;
});</syntaxhighlight>

=={{header|SQL PL}}==
{{works with|Db2 LUW}} version 9.7 or higher.
With SQL PL:
<syntaxhighlight lang="sql pl">
--#SET TERMINATOR @

SET SERVEROUTPUT ON @

BEGIN
 DECLARE TYPE NUMBERS AS SMALLINT ARRAY[5];
 DECLARE NUMBERS NUMBERS;
 DECLARE I SMALLINT;

 SET I = 1;
 WHILE (I <= 5) DO
  SET NUMBERS[I] = I;
  SET I = I + 1;
 END WHILE;

 BEGIN
  DECLARE PROCEDURE PRINT_SQUARE (
    IN VALUE SMALLINT
   )
  BEGIN
   CALL DBMS_OUTPUT.PUT(VALUE * VALUE || ' ');
  END;

  SET I = 1;
  WHILE (I <= 5) DO
   CALL PRINT_SQUARE(NUMBERS[I]);
   SET I = I + 1;
  END WHILE;
  CALL DBMS_OUTPUT.PUT_LINE('');
 END;
END @
</syntaxhighlight>
Output:
<pre>
db2 -td@
db2 => BEGIN
...
db2 (cont.) => END @
DB20000I  The SQL command completed successfully.

1 4 9 16 25 
</pre>

=={{header|Standard ML}}==
<syntaxhighlight lang="standard ml">
map f l
</syntaxhighlight>
i.e.
<syntaxhighlight lang="standard ml">
map (fn x=>x+1) [1,2,3];; (* [2,3,4] *)
</syntaxhighlight>

=={{header|Stata}}==
There is no 'map' function in Mata, but it's easy to implement. Notice that you can only pass functions that are written in Mata, no builtin ones. For instance, the trigonometric functions (cos, sin) or the exponential are builtin. To pass a builtin function to another function, one needs to write a wrapper in Mata. See also Stata help about '''[https://www.stata.com/help.cgi?m2_pointers pointers]''' and '''[https://www.stata.com/help.cgi?m2_ftof passing functions to functions]'''. There are two versions of the function: one to return a numeric array, another to return a string array.

<syntaxhighlight lang="stata">function map(f,a) {
	nr = rows(a)
	nc = cols(a)
	b = J(nr,nc,.)
	for (i=1;i<=nr;i++) {
		for (j=1;j<=nc;j++) b[i,j] = (*f)(a[i,j])
	}
	return(b)
}

function maps(f,a) {
	nr = rows(a)
	nc = cols(a)
	b = J(nr,nc,"")
	for (i=1;i<=nr;i++) {
		for (j=1;j<=nc;j++) b[i,j] = (*f)(a[i,j])
	}
	return(b)
}

function square(x) {
	return(x*x)
}</syntaxhighlight>

'''Output'''

<pre>: map(&square(),(1,2,3\4,5,6))
        1    2    3
    +----------------+
  1 |   1    4    9  |
  2 |  16   25   36  |
    +----------------+</pre>

=={{header|SuperCollider}}==
Actually, there is a builtin <tt>squared</tt> operator:
<syntaxhighlight lang="supercollider">[1, 2, 3].squared  // returns [1, 4, 9]</syntaxhighlight>
Anything that is a <tt>Collection</tt> can be used with <tt>collect</tt>:
<syntaxhighlight lang="supercollider">[1, 2, 3].collect { |x| x * x }</syntaxhighlight>
[[List Comprehension#SuperCollider|List comprehension]] combined with a higher-order function can also be used:
<syntaxhighlight lang="supercollider">var square = { |x| x * x };
var map = { |fn, xs|
  all {: fn.value(x), x <- xs };
};
map.value(square, [1, 2, 3]);</syntaxhighlight>

=={{header|Swift}}==
<syntaxhighlight lang="swift">func square(n: Int) -> Int {
    return n * n
}

let numbers = [1, 3, 5, 7]

let squares1a = numbers.map(square)         // map method on array

let squares1b = numbers.map {x in x*x}      // map method on array with anonymous function

let squares1b = numbers.map { $0 * $0 }      // map method on array with anonymous function and unnamed parameters

let isquares1 = numbers.lazy.map(square)   // lazy sequence</syntaxhighlight>

=={{header|Tailspin}}==
<syntaxhighlight lang="tailspin">
def numbers: [1,3,7,10];

templates cube
  $ * $ * $ !
end cube

// Using inline array templates (which also allows access to index by $i)
$numbers -> \[i]($ * $i !\) -> !OUT::write
$numbers -> \[i]($ * $ !\) -> !OUT::write
$numbers -> \[i]($ -> cube !\) -> !OUT::write

// Using array literal and deconstructor
[ $numbers... -> $ * $ ] -> !OUT::write
[ $numbers... -> cube ] -> !OUT::write
</syntaxhighlight>

=={{header|Tcl}}==

If I wanted to call "<tt>myfunc</tt>" on each element of <tt>dat</tt> and <tt>dat</tt> were a list:
<syntaxhighlight lang="tcl">foreach var $dat {
    myfunc $var
}</syntaxhighlight>
This does not retain any of the values returned by <tt>myfunc</tt>.

if <tt>dat</tt> were an (associative) array, however:
<syntaxhighlight lang="tcl">foreach name [array names dat] {
    myfunc $dat($name)
}</syntaxhighlight>

More functional, with a simple <code>map</code> function:
<syntaxhighlight lang="tcl">proc map {f list} {
   set res {}
   foreach e $list {lappend res [$f $e]}
   return $res
}
proc square x {expr {$x*$x}}

% map square {1 2 3 4 5}
1 4 9 16 25</syntaxhighlight>

=={{header|TI-89 BASIC}}==

<syntaxhighlight lang="ti89b">© For no return value
Define foreach(fe_cname,fe_list) = Prgm
  Local fe_i
  For fe_i,1,dim(fe_list)
    #fe_cname(fe_list[fe_i])
  EndFor
EndPrgm

© For a list of results
Define map(map_cnam,map_list) = seq(#map_cnam(map_list[map_i]),map_i,1,dim(map_list))

Define callback(elem) = Prgm
  Disp elem
EndPrgm

foreach("callback", {1,2,3,4,5})
Disp map("√", {1,2,3,4,5})</syntaxhighlight>

{{Out}}
<math>1</math><br>
<math>2</math><br>
<math>3</math><br>
<math>4</math><br>
<math>5</math><br>
<math>\begin{Bmatrix}1 & \sqrt{2} & \sqrt{3} & 2 & \sqrt{5}\end{Bmatrix}</math>

=={{header|TIScript}}==

JavaScript alike:

<syntaxhighlight lang="javascript">var a = [1, 2, 3, 4, 5];
a.map(function(v) { return v * v; })
</syntaxhighlight>

Using short form of lambda notation:
<syntaxhighlight lang="javascript">var a = [1, 2, 3, 4, 5];
a.map( :v: v*v );
</syntaxhighlight>

=={{header|Toka}}==

<syntaxhighlight lang="toka">( array count function -- )
{
  value| array fn |
  [ i array ] is I
  [ to fn swap to array 0 swap [ I array.get :stack fn invoke I array.put ] countedLoop ]
} is map-array

( Build an array )
5 cells is-array a
10 0 a array.put
11 1 a array.put
12 2 a array.put
13 3 a array.put
14 4 a array.put

( Add 1 to each item in the array )
a 5  [ 1 + ] map-array</syntaxhighlight>

=={{header|TorqueScript}}==

--[[User:Elm|Elm]] 03:41, 18 June 2012 (UTC)

Callbacks:

<syntaxhighlight lang="torquescript">
function map(%array,%arrayCount,%function)
{
	for(%i=0;%i<%arrayCount;%i++)
	{
		eval("%a = "@%array@"["@%i@"];");
		eval(""@%function@"("@%a@");");
	}
}
</syntaxhighlight>

Now to set up an array:

<syntaxhighlight lang="torquescript">
$array[0] = "Hello.";
$array[1] = "Hi.";
$array[2] = "How are you?";
</syntaxhighlight>

Now to call the function correctly:

<syntaxhighlight lang="torquescript">
map("$array",3,"echo");
</syntaxhighlight>

Which should result in:

<syntaxhighlight lang="torquescript">
=> Hello.

=> Hi.

=> How are you?
</syntaxhighlight>

=={{header|TXR}}==

Print 1 through 10 out of a vector, using <code>prinl</code> the callback, right from the system shell command prompt:

<syntaxhighlight lang="bash">$ txr -e '[mapdo prinl #(1 2 3 4 5 6 7 8 9 10)]'
1
2
3
4
5
6
7
8
9
10</syntaxhighlight>

<code>mapdo</code> is like <code>mapcar</code> but doesn't accumulate a list, suitable for imperative programming situations when the function is invoked to perform a side effect.

TXR extends Lisp list processing primitives to work with vectors and strings also, which is why <code>mapdo</code> cheerfully traverses a vector.

=={{header|uBasic/4tH}}==
We cannot transfer the array address, since uBasic/4tH has only got one, but we can transfer the function pointer and size.
<syntaxhighlight lang="text">S = 5                                  ' Size of the array

For x = 0 To S - 1                     ' Initialize array
  @(x) = x + 1
Next

Proc _MapArray (_SquareRoot, S)        ' Call mapping procedure

For x = 0 To S - 1                     ' Print results
  Print "SQRT(";x+1;") = ";Using "#.####";@(x)
Next

For x = 0 To S - 1                     ' Reinitialize array
  @(x) = x + 1
Next

Proc _MapArray (_Cosine, S)            ' Call mapping procedure

Print : For x = 0 To S - 1             ' Print results
  Print "COS(";x+1;") = ";Using "#.####";@(x)
Next

End


_MapArray Param(2)                     ' Param(1) = function
  Local (1)                            ' Param(2) = array size

  For c@ = 0 To b@ - 1
    @(c@) = FUNC(a@(@(c@)))
  Next
Return


_SquareRoot Param (1)                  ' This is an integer SQR subroutine
  Local (2)

  b@ = (10^(4*2)) * a@                 ' Output is scaled by 10^4
  a@ = b@

  Do
    c@ = (a@ + (b@ / a@))/2
  Until (Abs(a@ - c@) < 2)
    a@ = c@
  Loop

Return (c@)


_Cosine Param(1)                       ' This is an integer COS subroutine
  Push Abs((a@*10000)%62832)           ' Output is scaled by 10^4
  If Tos()>31416 Then Push 62832-Pop()
  Let a@=Tos()>15708
  If a@ Then Push 31416-Pop()
  Push Tos()
  Push (Pop()*Pop())/10000
  Push 10000+((10000*-(Tos()/56))/10000)
  Push 10000+((Pop()*-(Tos()/30))/10000)
  Push 10000+((Pop()*-(Tos()/12))/10000)
  Push 10000+((Pop()*-(Pop()/2))/10000)
  If a@ Then Push -Pop()               ' Result is directly transferred
Return                                 ' through the stack</syntaxhighlight>
{{out}}
<pre>SQRT(1) = 1.0000
SQRT(2) = 1.4142
SQRT(3) = 1.7320
SQRT(4) = 2.0000
SQRT(5) = 2.2360

COS(1) = 0.5403
COS(2) = -0.4162
COS(3) = -0.9901
COS(4) = -0.6537
COS(5) = 0.2837

0 OK, 0:514</pre>

=={{header|UNIX Shell}}==
{{works with|Bourne Shell}}
<syntaxhighlight lang="bash">map() {
	map_command=$1
	shift
	for i do "$map_command" "$i"; done
}
list=1:2:3
(IFS=:; map echo $list)</syntaxhighlight>

{{works with|ksh93}}
{{works with|pdksh}}
{{works with|zsh}}
<syntaxhighlight lang="bash">map() {
	typeset command=$1
	shift
	for i do "$command" "$i"; done
}
set -A ary 1 2 3
map print "${ary[@]}"</syntaxhighlight>

{{works with|zsh}}
<syntaxhighlight lang="bash">map(){for i ($*[2,-1]) $1 $i}
a=(1 2 3)
map print $a</syntaxhighlight>

=={{header|Ursala}}==
The * is a built-in map operator.
This example shows a map of the successor function over a list of natural numbers.
<syntaxhighlight lang="ursala">#import nat

#cast %nL

demo = successor* <325,32,67,1,3,7,315></syntaxhighlight>
{{Out}}
<pre>
<326,33,68,2,4,8,316>
</pre>

=={{header|V}}==
apply squaring (dup *) to each member of collection
<syntaxhighlight lang="v">[1 2 3 4] [dup *] map</syntaxhighlight>

=={{header|VBA}}==
<syntaxhighlight lang="vb">
Option Explicit

Sub Main()
Dim arr, i
    'init
    arr = Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

    'Loop and apply a function (Fibonacci) to each element
    For i = LBound(arr) To UBound(arr): arr(i) = Fibonacci(arr(i)): Next
    
    'return
    Debug.Print Join(arr, ", ")
End Sub

Private Function Fibonacci(N) As Variant
    If N <= 1 Then
        Fibonacci = N
    Else
        Fibonacci = Fibonacci(N - 1) + Fibonacci(N - 2)
    End If
End Function</syntaxhighlight>
{{out}}
<pre>0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55</pre>

=={{header|VBScript}}==
I really have my doubts as to whether this really counts as a callback. 
I used the same thing in the solution to Amb.

=====Implementation=====
<syntaxhighlight lang="vb">
class callback
	dim sRule

	public property let rule( x )
		sRule = x
	end property
	
	public default function applyTo(a)
		dim p1
		for i = lbound( a ) to ubound( a )
			p1 = a( i )
			a( i ) = eval( sRule )
		next
		applyTo = a
	end function
end class
</syntaxhighlight>

=====Invocation=====
<syntaxhighlight lang="vb">
dim a1
dim cb
set cb = new callback

cb.rule = "ucase(p1)"
a1 = split("my dog has fleas", " " )
cb.applyTo a1
wscript.echo join( a1, " " )

cb.rule = "p1 ^ p1"
a1 = array(1,2,3,4,5,6,7,8,9,10)
cb.applyto a1
wscript.echo join( a1, ", " )
</syntaxhighlight>

{{Out}}
<pre>
MY DOG HAS FLEAS
1, 4, 27, 256, 3125, 46656, 823543, 16777216, 387420489, 10000000000
</pre>

=={{header|Vim Script}}==
<code>map()</code> works with lists and dictionaries. 
The second argument is an expression string where <code>v:val</code> is replaced by the current value and <code>v:key</code> by the current key (for lists the key is the index). 
The result of evaluating the string will be the new value. 
The list/dictionary is modified in place.
<syntaxhighlight lang="vim">echo map([10, 20, 30], 'v:val * v:val')
echo map([10, 20, 30], '"Element " . v:key . " = " . v:val')
echo map({"a": "foo", "b": "Bar", "c": "BaZ"}, 'toupper(v:val)')
echo map({"a": "foo", "b": "Bar", "c": "BaZ"}, 'toupper(v:key)')</syntaxhighlight>

{{Out}}
<pre>[100, 400, 900]                                                                 
['Element 0 = 10', 'Element 1 = 20', 'Element 2 = 30']                          
{'a': 'FOO', 'b': 'BAR', 'c': 'BAZ'}                                            
{'a': 'A', 'b': 'B', 'c': 'C'}</pre>

=={{header|Visual Basic .NET}}==
'''Compiler:''' >= Visual Studio 2008

The .NET framework has got us covered.
 
System.Array.ForEach(T(), Action(Of T)) maps a non-value-returning callback,

System.Linq.Enumerable.Select(Of TSource,TResult)(IEnumerable(Of TSource), Func(Of TSource, TResult)) provides a way to lazily map a function, resulting in an IEnumerable(Of T),

and System.Linq.Enumerable.ToArray(Of TSource)(IEnumerable(Of TSource)) eagerly converts the enumerable to an array.

<syntaxhighlight lang="vbnet">Module Program
    Function OneMoreThan(i As Integer) As Integer
        Return i + 1
    End Function

    Sub Main()
        Dim source As Integer() = {1, 2, 3}

        ' Create a delegate from an existing method.
        Dim resultEnumerable1 = source.Select(AddressOf OneMoreThan)

        ' The above is just syntax sugar for this; extension methods can be called as if they were instance methods of the first parameter.
        resultEnumerable1 = Enumerable.Select(source, AddressOf OneMoreThan)

        ' Or use an anonymous delegate.
        Dim resultEnumerable2 = source.Select(Function(i) i + 1)

        ' The sequences are the same. 
        Console.WriteLine(Enumerable.SequenceEqual(resultEnumerable1, resultEnumerable2))

        Dim resultArr As Integer() = resultEnumerable1.ToArray()

        Array.ForEach(resultArr, AddressOf Console.WriteLine)
    End Sub
End Module</syntaxhighlight>

{{out}}
<pre>True
2
3
4</pre>

=={{header|Vorpal}}==
Given and array, A, and a function, F, mapping F over the elements of A is simple:
<syntaxhighlight lang="vorpal">A.map(F)</syntaxhighlight>
If F takes 2 arguments, x and , then simply pass them to map.  
They will be passed to F when as it is applied to each element of A.
<syntaxhighlight lang="vorpal">A.map(F, x, y)</syntaxhighlight>

=={{header|Wart}}==
<syntaxhighlight lang="wart">map prn '(1 2 3 4 5)</syntaxhighlight>

{{Out}}
<pre>1
2
3
4
5</pre>

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

let example => [3; 5; 2];

let double => a.stream example
-> s.map (* 2)
-> s.collect
;</syntaxhighlight>

In WDTE, mapping can be accomplished using the <code>stream</code> module. Streams are essentially lazy iterators. The <code>arrays</code> module provides a function for creating a stream from an array, and then the <code>stream</code> module's functions can be used to perform a map operation. <code>collect</code> runs the iteration, collecting the elements yielded in a new array.

=={{header|Wren}}==
<syntaxhighlight lang="wren">var arr = [1, 2, 3, 4, 5]
arr = arr.map { |x| x * 2 }.toList
arr = arr.map(Fn.new { |x| x / 2 }).toList
arr.each { |x| System.print(x) }</syntaxhighlight>

{{out}}
<pre>
1
2
3
4
5
</pre>

=={{header|XBS}}==
<syntaxhighlight lang="xbs">func map(arr:array,callback:function){
	set newArr:array = [];
	foreach(k,v as arr){
		newArr[k]=callback(v,k,arr);
	}
	send newArr;
}
 
set arr:array = [1,2,3,4,5];
set result:array = map(arr,func(v){
	send v*2;
});
 
log(arr.join(", "));
log(result.join(", "));</syntaxhighlight>
{{out}}
<pre>
1, 2, 3, 4, 5
2, 4, 6, 8, 10
</pre>

=={{header|Yabasic}}==
<syntaxhighlight lang="yabasic">sub map(f$, t())
    local i

    for i = 1 to arraysize(t(), 1)
        t(i) = execute(f$, t(i))
    next i
end sub

sub add1(x)
    return x + 1
end sub

sub square(x)
    return x * x
end sub

dim t(10)

for i = 1 to 10
    t(i) = i
    print t(i), "\t";
next i
print

//map("add1", t())
map("square", t())

for i = 1 to 10
    print t(i), "\t";
next i
print</syntaxhighlight>

=={{header|Yacas}}==
<syntaxhighlight lang="yacas">Sin /@ {1, 2, 3, 4}

MapSingle(Sin, {1,2,3,4})

MapSingle({{x}, x^2}, {1,2,3,4})
</syntaxhighlight>

=={{header|Z80 Assembly}}==
<syntaxhighlight lang="z80">Array:
byte &01,&02,&03,&04,&05
Array_End:

foo:
ld hl,Array
ld b,Array_End-Array ;ld b,5

bar:
inc (hl)
inc (hl)
inc (hl)
inc hl     ;next entry in array
djnz bar</syntaxhighlight>

{{out}}
The program above doesn't show the new values but here they are:
<pre>
&04,&05,&06,&07,&08   
</pre>

=={{header|Zig}}==
<syntaxhighlight lang="zig">pub fn main() !void {
    var array = [_]i32{1, 2, 3}; 
    apply(@TypeOf(array[0]), array[0..], func);
}

fn apply(comptime T: type, a: []T, f: fn(T) void) void {
    for (a) |item| {
        f(item);
    }
}

fn func(a: i32) void {
    const std = @import("std");
    std.debug.print("{d}\n", .{a-1});
}</syntaxhighlight>

=={{header|zkl}}==
<syntaxhighlight lang="zkl">L(1,2,3,4,5).apply('+(5))</syntaxhighlight>
{{Out}}
<pre>
L(6,7,8,9,10)
</pre>

=={{header|zonnon}}==
<syntaxhighlight lang="zonnon">
module Main;
type
	Callback = procedure (integer): integer;
	Vector = array {math} * of integer;

procedure Power(i:integer):integer;
begin
	return i*i;
end Power;

procedure Map(x: Vector;p: Callback): Vector;
var
	i: integer;
	r: Vector;
begin
	r := new Vector(len(x));
	for i := 0 to len(x) - 1 do	
		r[i] := p(i);
	end;
	return r
end Map;

procedure Write(x: Vector);
var
	i: integer;
begin
	for i := 0 to len(x) - 1 do
		write(x[i]:4)
	end;
	writeln
end Write;

var
	x,y: Vector;

begin
	x := [1,2,3,4,5];
	Write(Map(x,Power))
end Main.
</syntaxhighlight>
{{Out}}
<pre>
   0   1   4   9  16
</pre>

=={{header|ZX Spectrum Basic}}==
<syntaxhighlight lang="zxbasic">10 LET a$="x+x"
20 LET b$="x*x"
30 LET c$="x+x^2"
40 LET f$=c$: REM Assign a$, b$ or c$
150 FOR i=1 TO 5
160 READ x
170 PRINT x;" = ";VAL f$
180 NEXT i
190 STOP 
200 DATA 2,5,6,10,100
</syntaxhighlight>

{{omit from|gnuplot}}
{{omit from|LaTeX}}
{{omit from|Make}}
{{omit from|NSIS}}
{{omit from|PlainTeX}}