PHP array_walk_recursive() 函数

<?php
    function myfunction($value, $key)
    {
        echo "The key $key has the value 
	$value<br>";
    }
    $a1 = array("a" => "red", "b" => "green");
    $a2 = array($a1, "1" => "blue", "2" => "yellow");
    array_walk_recursive($a2, "myfunction");
    ?>