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PHP array_map() Function

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.

Syntax

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

Parameter	Description
function	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

Tips and Notes

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

Example 1

<?php
function myfunction($v) 
{
if ($v==="Dog")
	{
	return "Fido";
	}
return $v;
}
$a=array("Horse","Dog","Cat");
print_r(array_map("myfunction",$a));
?>

The output of the code above will be:

Array ( [0] => Horse [1] => Fido [2] => Cat )

Example 2

Using the more than one parameter.

<?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));
?>

The output of the code above will be:

Array ( [0] => different [1] => same [2] => different )

Example 3

Look what happens if you assign null as the functionname:

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

The output of the code above will be:

Array (
[0] => Array ( [0] => Dog [1] => Puppy )
[1] => Array ( [0] => Cat [1] => Kitten )
)

Complete PHP Array Reference