php小白数组求解 根据某一个键值重新排序数组 给分100

这样一个json数组
[ {"id":"1","name":"21g","dis":"33"},
  {"id":"2","name":"21g","dis":"22"},
  {"id":"3","name":"21g","dis":"3"},
  {"id":"4","name":"21g","dis":"5"},
  {"id":"5","name":"21g","dis":"12"}]    
需要根据dis从小到大排序成
[{"id":"3","name":"21g","dis":"3"},
 {"id":"4","name":"21g","dis":"5"},
 {"id":"5","name":"21g","dis":"12"},
 {"id":"2","name":"21g","dis":"22"},
 {"id":"1","name":"21g","dis":"33"}]

求步骤详情  在线等      急！！！

回复讨论(解决方案)

$s =<<< TXT[ {"id":"1","name":"21g","dis":"33"},  {"id":"2","name":"21g","dis":"22"},  {"id":"3","name":"21g","dis":"3"},  {"id":"4","name":"21g","dis":"5"},  {"id":"5","name":"21g","dis":"12"}]    TXT;$a = json_decode($s, true);foreach($a as $v) $r[] = $v['dis'];array_multisort($r, $a);echo json_encode($a);

谢谢谢谢！！  已经弄好了！