按多个属性对数组中的对象进行排序（可能性不存在）

Question

我正在尝试对该数组进行排序：

[
  {
    "id": 877234004,
    "name": "app.js",
    "type": "FILE",
    "parentId": 877234003
  },
  {
    "id": 877234010,
    "name": "project",
    "type": "DIRECTORY"
  },
  {
    "id": 877234002,
    "name": "src",
    "type": "DIRECTORY",
    "parentId": 877234010
  },
  {
    "id": 877234003,
    "name": "app",
    "type": "DIRECTORY",
    "parentId": 877234002
  }
]

如您所见，有些对象没有parentId。我需要将其放在顶部，其余按id排序。

这是我的代码：

input.sort(function (a, b) {
    if (typeof a.parentId === 'undefined')) 
      return -1;
    else
      return a.id - b.id;
  });

虽然不起作用。可以这样做吗？

预期结果：

[
  {
    "id": 877234010,
    "name": "project",
    "type": "DIRECTORY"
  },
  {
    "id": 877234002,
    "name": "src",
    "type": "DIRECTORY",
    "parentId": 877234010
  },
  {
    "id": 877234003,
    "name": "app",
    "type": "DIRECTORY",
    "parentId": 877234002
  },
  {
    "id": 877234004,
    "name": "app.js",
    "type": "FILE",
    "parentId": 877234003
  }
]

预先感谢

Answer 1

我建议使用lodash js库

var arr = [
  {
    "id": 877234004,
    "name": "app.js",
    "type": "FILE",
    "parentId": 877234003
  },
  {
    "id": 877234010,
    "name": "project",
    "type": "DIRECTORY"
  },
  {
    "id": 877234002,
    "name": "src",
    "type": "DIRECTORY",
    "parentId": 877234010
  },
  {
    "id": 877234003,
    "name": "app",
    "type": "DIRECTORY",
    "parentId": 877234002
  }
];

var sortedArr = _.orderBy(arr, 'parentId', 'desc');

console.log(sortedArr);

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.11/lodash.min.js"></script>

Answer 2

需要测试A和B并反转。如果A缺少道具，则使用-1，如果B使用+1

let arr = [{
    "id": 877234004,
    "name": "app.js",
    "type": "FILE",
    "parentId": 877234003
  },
  {
    "id": 877234010,
    "name": "project",
    "type": "DIRECTORY"
  },
  {
    "id": 877234002,
    "name": "src",
    "type": "DIRECTORY",
    "parentId": 877234010
  },
  {
    "id": 877234003,
    "name": "app",
    "type": "DIRECTORY",
    "parentId": 877234002
  }
];

const sortPredicate = (a,b) => {
  if (a.hasOwnProperty('parentId') === false) {
    return -1;
  } else if(b.hasOwnProperty('parentId') === false) {
    return 1;
  } else {
    return a.id - b.id;
  }
};


console.log(arr.sort(sortPredicate));