PHP 数组函数 array_walk_recursive()

<?php
   function call_back_function($value,$key) {
      echo "The key $key has the value $value \n";
   }

   $input1 = array("a"=>"green", "b"=>"brown", "c"=>"blue" );
   $input2 = array($input1, "d"=>"yellow", "e"=>"black");

   array_walk_recursive($input2,"call_back_function");
?>