js:数组的排序

 

<script type="text/javascript">
  var ar = [2,1,11,13,4,3,9,7];
  alert(ar);
  //倒序
  alert(ar.reverse());
  //升序 (如果是两位,十位单独排序,再个位排序,见下图)
  alert(ar.sort());
  //升序, -(a-b)是降序
  function f(a,b){
      return a-b;
     /* if(a > b) return 1;
      if(a < b) return -1;
      if(a == b) return 0;*/
      }
  alert(ar.sort(f));
</script>