如何将关联数组转换为已排序的字符串数组？

Question

如何转换此js对象

 var obj1 =  {"user1":28, "user2":87, "user3":56};

进入一个字符串数组，按值排序，如下所示：

["user2","user3","user1"]

Answer 1

使用此：

var obj1 =  {"user1":28, "user2":87, "user3":56};
var a = Object.keys(obj1).sort(function(x,y){return obj1[y]-obj1[x]})
console.log(a);

输出：

["user2", "user3", "user1"]