php自定义排序uasort函数示例【二维数组按指定键值排序】

/* * 二维数组按指定键值排须 */function arr_sort($array,$key,$order="asc"){//asc是升序 desc是降序//按 I<L<M<H 排序  $arr_nums=$arr=array();  foreach($array as $k=>$v){    $arr_nums[$k]=$v[$key];  }  if($order=='asc'){    uasort($arr_nums,'my_sort_asc');  }else{    uasort($arr_nums,'my_sort_desc');  }  foreach($arr_nums as $k=>$v){    $arr[$k]=$array[$k];  }  return $arr;}function my_sort_desc($a,$b){  if($a==$b) return 0;  if($a=='I' && $b!='I') return 1;  if($a=='L' && $b!='I') return 1;  if($a=='L' && $b=='I') return -1;  if($a=='M' && $b!='H') return -1;  if($a=='M' && $b=='H') return 1;  if($a=='H' && $b!='H') return -1;}function my_sort_asc($a,$b){  if($a==$b) return 0;  if($a=='I' && $b!='I') return -1;  if($a=='L' && $b!='I') return -1;  if($a=='L' && $b=='I') return 1;  if($a=='M' && $b!='H') return 1;  if($a=='M' && $b=='H') return -1;  if($a=='H' && $b!='H') return 1;}