代码如下：

　　　　　function sortBy(attr,rev){             //第二个参数没有传递 默认升序排列             if(rev ==  undefined){                 rev = 1;             }else{                 rev = (rev) ? 1 : -1;             }                          return function(a,b){                 a = a[attr];                 b = b[attr];                 if(a < b){                     return rev * -1;                 }                 if(a > b){                     return rev * 1;                 }                 return 0;             }         }

        var list = [             {                 a:8,                 b:[3,4]             },             {                 a:1,                 b:[1,2]             },             {                 a:18,                 b:[5,6]             }         ]         list.sort(sortBy('a')) // == list.sort(sortBy('a'),true)         console.log(list);

 

效果如下：

 

 

 逆序：

list.sort(sortBy('a'),false)