array_map

Description
Syntax
Examples
Links

Description

The array_map of Array for PHP applies the callback to the elements of the given arrays.

Syntax

array_map(
    ?callable $callback,
    array $array,
    array ...$arrays
): array

Parameters

callback

A callable to run for each element in each array.

null can be passed as a value to callback to perform a zip operation on multiple arrays. If only array is provided, array_map() will return the input array.

array

An array to run through the callback function.

arrays

Supplementary variable list of array arguments to run through the callback function.

Return

Returns an array containing the results of applying the callback function to the corresponding value of array (and arrays if more arrays are provided) used as arguments for the callback.

The returned array will preserve the keys of the array argument if and only if exactly one array is passed. If more than one array is passed, the returned array will have sequential integer keys.

Examples

1 · callback array

<?

function myfunction($myparameter)
{
    return $myparameter * 10;
}

$callback = "myfunction";
$array = array("a" => 0, "b" => 1, "c" => 2, "d" => 3, "e" => 4);

$return = array_map($callback, $array);

print_r($return);

?>

Array
(
    [a] => 0
    [b] => 10
    [c] => 20
    [d] => 30
    [e] => 40
)

2 · callback array · null

<?

$callback = null;
$array = array("a" => 0, "b" => 1, "c" => 2, "d" => 3, "e" => 4);

$return = array_map($callback, $array);

print_r($return);

?>

Array
(
    [a] => 0
    [b] => 1
    [c] => 2
    [d] => 3
    [e] => 4
)

3 · arrays

<?

function myfunction($myparameter1, $myparameter2)
{
    return array($myparameter1 * 10, $myparameter2);
}

$callback = "myfunction";
$array = array("a" => 0, "b" => 1, "c" => 2, "d" => 3, "e" => 4);
$arrays = array("zero", "one", "two", "three", "four");

$return = array_map($callback, $array, $arrays);

print_r($return);

?>

Array
(
    [0] => Array
        (
            [0] => 0
            [1] => zero
        )

    [1] => Array
        (
            [0] => 10
            [1] => one
        )

    [2] => Array
        (
            [0] => 20
            [1] => two
        )

    [3] => Array
        (
            [0] => 30
            [1] => three
        )

    [4] => Array
        (
            [0] => 40
            [1] => four
        )

)

4 · arrays · null

<?

$callback = null;
$array = array("a" => 0, "b" => 1, "c" => 2, "d" => 3, "e" => 4);
$arrays = array("zero", "one", "two", "three", "four");

$return = array_map($callback, $array, $arrays);

print_r($return);

?>

Array
(
    [0] => Array
        (
            [0] => 0
            [1] => zero
        )

    [1] => Array
        (
            [0] => 1
            [1] => one
        )

    [2] => Array
        (
            [0] => 2
            [1] => two
        )

    [3] => Array
        (
            [0] => 3
            [1] => three
        )

    [4] => Array
        (
            [0] => 4
            [1] => four
        )

)