javascript - Object.entries()，为什么我的数组默认按数字排序？

Question

我正在编写一个简单的代码练习解决方案，发现似乎是 object.entries()进行内部数字升序排序。自 docs 以来，我一直希望自己必须对键值对进行排序。说如果你需要一个特定的订单，你必须做一个排序。为什么会发生这种情况，我可以依靠这种行为吗？

/*
Given an input of [1,2,4,591,392,391,2,5,10,2,1,1,1,20,20], 
make a function that organizes these into individual array that is ordered. 
The above input should return:
[[1,1,1,1],[2,2,2],4,5,10,[20,20],391,392,591].
*/
const cleanTheRoom = (mess) => { 
  let hash = {};
  for (let i = 0; i < mess.length; i++) {
    (hash.hasOwnProperty(mess[i])) ? hash[mess[i]]++ : hash[mess[i]] = 1;
  }
  const clean = [];
  for (const [key, value] of Object.entries(hash)) {
    (value > 1) ? clean.push(Array(value).fill(key)) : clean.push(key);
  }
  return clean;
}

let cleaned = cleanTheRoom(
  [1,2,4,591,392,391,2,5,10,2,1,1,1,20,20]
);

console.log(cleaned);

Answer 1

Object.entries 使用规范操作 EnumerableOwnPropertyKeys ，它又使用对象的 [[OwnPropertyKeys]]，对于大多数对象(包括数组)来说，它是 OrdinaryOwnPropertyKeys .该操作专门针对看起来像数组索引的特殊情况下的属性名称，并按数字顺序列出它们。算法是:

1. Let keys be a new empty List.
2. For each own property key P of O such that P is an array index, in ascending numeric index order, do
   1. Add P as the last element of keys.
3. For each own property key P of O such that Type(P) is String and P is not an array index, in ascending chronological order of property creation, do
   1. Add P as the last element of keys.
4. For each own property key P of O such that Type(P) is Symbol, in ascending chronological order of property creation, do
   1. Add P as the last element of keys.
5. Return keys.