二维数组排序 具有通用性（今天的面试题）

<?php /************************************ * Allows sorting multi-dimensional * arrays by a specific key and in * asc or desc order **/ class multiSort { var $key; //key in your array //runs the sort, and returns sorted array function run ($myarray, $key_to_sort, $type_of_sort = '') { $this->key = $key_to_sort; if ($type_of_sort == 'desc') uasort($myarray, array($this, 'myreverse_compare')); else uasort($myarray, array($this, 'mycompare')); return $myarray; } //for ascending order function mycompare($x, $y) { if ( $x[$this->key] == $y[$this->key] ) return 0; else if ( $x[$this->key] < $y[$this->key] ) return -1; else return 1; } //for descending order function myreverse_compare($x, $y) { if ( $x[$this->key] == $y[$this->key] ) return 0; else if ( $x[$this->key] > $y[$this->key] ) return -1; else return 1; } } ?>