PHP array_map() Function

Example

Send each value of an array to a function, multiply each value by itself, and return an array with the new values:

<?php
function myfunction($v)
{
return($v*$v);
}

$a=array(1,2,3,4,5);
print_r(array_map("myfunction",$a));
?>

Definition and Usage

The array_map() function sends each value of an array to a user-made function, and returns an array with new values, given by the user-made function.

Tip: You can assign one array to the function, or as many as you like.

Syntax

array_map(myfunction, array1, array2, array3, ...)

Parameter Values

Parameter	Description
myfunction	Required. The name of the user-made function, or null
array1	Required. Specifies an array
array2	Optional. Specifies an array
array3	Optional. Specifies an array

Technical Details

Return Value:	Returns an array containing the values of array1, after applying the user-made function to each one
PHP Version:	4.0.6+

More Examples

Example

Using a user-made function to change the values of an array:

<?php
function myfunction($v)
{
if ($v==="Dog")
{
return "Fido";
}
return $v;
}

$a=array("Horse","Dog","Cat");
print_r(array_map("myfunction",$a));
?>

Try it Yourself »

Example

Using two arrays:

<?php
function myfunction($v1,$v2)
{
if ($v1===$v2)
{
return "same";
}
return "different";
}

$a1=array("Horse","Dog","Cat");
$a2=array("Cow","Dog","Rat");
print_r(array_map("myfunction",$a1,$a2));
?>

Try it Yourself »

Example

Change all letters of the array values to uppercase:

<?php
function myfunction($v)
{
$v=strtoupper($v);
return $v;
}

$a=array("Animal" => "horse", "Type" => "mammal");
print_r(array_map("myfunction",$a));
?>

Try it Yourself »

Example

Assign null as the function name:

<?php
$a1=array("Dog","Cat");
$a2=array("Puppy","Kitten");
print_r(array_map(null,$a1,$a2));
?>

Try it Yourself »

❮ PHP Array Reference