如何將關聯數組轉換為已排序的字符串數組？

Question

我該如何轉換這個js對象

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

到一個字符串數組，按值排序，如下所示：

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

Answer 1

用這個：

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);

輸出：

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