Question

我有一个对象数组。在每个这些对象中，只有几个具有属性，我想对数组进行排序，将具有该属性的那些对象放在顶部。

Ex-

arr= [{key1: "obj1val1", key2 :"obj1val2"}, 
      {key2 :"obj2val2"}, 
      {key1: "obj3val3", key2 :"obj3val3"},
      {key2 :"obj4val1"},
      {key1: "obj5val1", key2 :"obj5val2"}
]

按key1排序

Expected Result - [{key1: "obj1val1", key2 :"obj1val2"}, 
                   {key1: "obj3val3", key2 :"obj3val3"},
                   {key1: "obj5val1", key2 :"obj5val2"}, 
                   {key2 :"obj2val2"}, 
                   {key2 :"obj4val1"}]

我尝试了以下方法-

sort : function(arr) {
              var copyArr = arr.slice();
              var newArr = [];
              for(var i=0; i<arr.length; i++){
                if(arr[i].key1){
                  newArr.push(arr[i]);
                    copyArr.splice(i, 1);
                }
              }
              Array.prototype.push.apply(newArr, copyArr);
              return newArr;
            }

不太准确，但是我发现上述方法存在差异。对于更大长度的数组，某些具有key1的对象不会移到顶部。可以通过JavaScript的内部sort方法来完成此操作吗？如果是，自定义函数将如何比较？

仅支持ES5方法。

Answer 1

这可以通过javascript的内部排序方法完成吗

是：只需选择具有以下属性的条目：

arr.sort(function(left, right) {
    return left.hasOwnProperty("key1") ? -1 : right.hasOwnProperty("key1") ? 1 : 0
});

实时示例：

var arr = [
    {key1: "obj1val1", key2 :"obj1val2"}, 
    {key2 :"obj2val2"}, 
    {key1: "obj3val3", key2 :"obj3val3"},
    {key2 :"obj4val1"},
    {key1: "obj5val1", key2 :"obj5val2"}
];
arr.sort(function(left, right) {
    return left.hasOwnProperty("key1") ? -1 : right.hasOwnProperty("key1") ? 1 : 0
});
console.log(arr);

如果您还想按该属性的值排序：

arr.sort(function(left, right) {
    var leftHas = left.hasOwnProperty("key1");
    var rightHas = right.hasOwnProperty("key1");
    if (leftHas && rightHas) {
      return left.key1.localeCompare(right.key1);
    }
    return leftHas ? -1 : rightHas ? 1 : 0;
});

实时示例：

var arr = [
    {key1: "obj1val1", key2 :"obj1val2"}, 
    {key2 :"obj2val2"}, 
    {key1: "obj3val3", key2 :"obj3val3"},
    {key2 :"obj4val1"},
    {key1: "obj5val1", key2 :"obj5val2"}
];
arr.sort(function(left, right) {
    var leftHas = left.hasOwnProperty("key1");
    var rightHas = right.hasOwnProperty("key1");
    if (leftHas && rightHas) {
      return left.key1.localeCompare(right.key1);
    }
    return leftHas ? -1 : rightHas ? 1 : 0;
});
console.log(arr);

Answer 2

您可以采用的一种变态方法：

arr.filter(obj => obj.hasOwnProperty('key1')).concat(arr.filter(obj => !obj.hasOwnProperty('key1')));

Answer 3

这是一个工作片段，可以提供您所需的结果，并且可以轻松扩展。它使用本机数组sort。

arr = [{
    key1: "obj1val1",
    key2: "obj1val2"
  },
  {
    key2: "obj2val2"
  },
  {
    key1: "obj3val3",
    key2: "obj3val3"
  },
  {
    key2: "obj4val1"
  },
  {
    key1: "obj5val1",
    key2: "obj5val2"
  }
]

const sorted = arr.sort((a, b) => {
  const k1 = a.key1 === undefined ? 0 : 1
  const k2 = b.key1 === undefined ? 0 : 2
  return k2- k1
})
console.log(sorted)

Answer 4

https://github.com/arraybrain/arraybrain

对于复杂数组的东西，您可以使用它

如果属性存在，则对对象数组进行排序

4 个答案: