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Last updated: Tue, 19 Sep 2006


(PHP 5)

array_walk_recursive --  Apply a user function recursively to every member of an array


bool array_walk_recursive ( array &input, callback funcname [, mixed userdata] )

Applies the user-defined function funcname to each element of the input array. This function will recur into deeper arrays. Typically, funcname takes on two parameters. The input parameter's value being the first, and the key/index second. If the optional userdata parameter is supplied, it will be passed as the third parameter to the callback funcname.

Returns TRUE on success or FALSE on failure.

Note: If funcname needs to be working with the actual values of the array, specify the first parameter of funcname as a reference. Then, any changes made to those elements will be made in the original array itself.

Example 1. array_walk_recursive() example

$sweet = array('a' => 'apple', 'b' => 'banana');
$fruits = array('sweet' => $sweet, 'sour' => 'lemon');

function test_print($item, $key) 
    echo "$key holds $item\n";

array_walk_recursive($fruits, 'test_print');

The above example will output:

a holds apple
b holds banana
sour holds lemon

You may notice that the key 'sweet' is never displayed. Any key that holds an array will not be passed to the function.

See also array_walk(), and information about the callback type.

Last updated: Tue, 19 Sep 2006