PHP: array_walk() function
PHP: Apply a user supplied function to every member of an array
The array_walk() function apply a user defined function to every element of an array. The user-defined function takes array's values and keys as parameters.
Note: array_walk() is not affected by the internal array pointer of the array. array_walk() will walk through the entire array regardless of pointer position.
Version:
(PHP 4 and above)
Syntax:
array_walk(input_array, user_function, user_data)
Parameters:
Name | Description | Required / Optional |
Type |
---|---|---|---|
input_array | The input array. | Required | Array |
user_function | The name of the userdefined function. | Required | - |
user_data | Additional parameter. If it is supplied, it will be passed as the third parameter to the user_function. | Optional | Mixed* |
*Mixed: Mixed indicates that a parameter may accept multiple (but not necessarily all) types.
Return value
TRUE on success or FALSE on failure.
Value Type: Boolean.
Example:
<?php
function w3rfunction($value,$key)
{
echo "w3resource $key has $value<br />";
}
$tutorials=array("tutorial1"=>"php","tutorial2"=>"xml","tutorial3"=>"javascript");
array_walk($tutorials,"w3rfunction");
?>
Output:
w3resource tutorial1 has php w3resource tutorial2 has xml w3resource tutorial3 has javascript
View the example in the browser
Practice here online:
See also
Previous: array_walk_ recursive
Next: arsort
PHP: Tips of the Day
Filters the collection using the given callback
Example:
<?php function tips_reject($items, $func) { return array_values(array_diff($items, array_filter($items, $func))); } print_r(tips_reject(['Apple', 'Pear', 'Kiwi', 'Banana'], function ($item) { return strlen($item) > 4; })); ?>
Output:
Array ( [0] => Pear [1] => Kiwi )
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