Check if an array is a multidimensional array.

is_multi_array.php

<?php
/**
 *  Check if an array is a multidimensional array.
 *
 *  @param   array   $arr  The array to check
 *  @return  boolean       Whether the the array is a multidimensional array or not
 */
function is_multi_array( $x ) {
    if( count( array_filter( $x,'is_array' ) ) > 0 ) return true;
    return false;
}