PHP排序函数有哪些？

//php排序函数实例
function array_sort($arr,$keys,$type='asc')
{
 echo'开始排序...'.'';
 $keysvalue = $new_array = array();
 foreach ($arr as $k=>$v)
 {
  $keysvalue[$k] = $v[$keys];
 }
 if($type == 'asc')
 {
  asort($keysvalue);
 }
 else
 {
  arsort($keysvalue);
 }
 reset($keysvalue);
 foreach ($keysvalue as $k=>$v)
 {
  $new_array[$k] = $arr[$k];
 }
 echo'排序结束...'.'';
 return $new_array;
}