array_walk_recursive Apply a user function recursively to every member of an array boolarray_walk_recursive arrayinput callbackfuncname mixeduserdata 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. &return.success; 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. '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'); ?> ]]> &example.outputs; 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.