Syntax of array_walk_recursive
bool array_walk_recursive(array input, string function[, mixed user_data])
Like array_walk(), calls the named function for each element in the array. Unlike that function, if an element’s value is an array, the function is called for each element in that array as well. The function is called with the element’s value, key, and optional user data as arguments. To ensure that the function works directly on the values of the array, define the first parameter of the function by reference. Returns true on success, false on failure
Example of array_walk
<?php
$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');
?>
a holds apple b holds banana sour holds lemon