Question

给定数组：

myArr = [
  {'a':1},
  {'b':1},
  {'b':2},
  {'a':1},
  {'b':2}
]

索引0，其对象为{'a':1}，我想取回数组： [{'b':1},{'b':2},{'b':2}]保留原始排序顺序。

即删除索引0中的对象以及所有其他等效对象。有优雅的方式吗？

Answer 1

如果你想删除同一个对象，很简单：

＆＃13;

    a1 = { a: 1 }
    b1 = { b: 1 }
    b2 = { b: 2 }
    myArr = [ a1, b1, b2, a1, b2 ]
    
    var filtered = myArr.filter(o => o != a1)
    console.log(filtered);
    // [ {b: 1}, {b: 2}, {b: 2} ]

＆＃13;

但是，如果要删除等效对象，则会变得复杂，因为默认情况下JavaScript没有对象等效性测试。您可以自己实现一个，也可以依赖其中一个库，如lodash：

＆＃13;

var myArr = [
  {'a':1},
  {'b':1},
  {'b':2},
  {'a':1},
  {'b':2}
];

var filtered = _.filter(myArr, o => !_.isEqual(o, {a: 1}));
console.log(filtered);
// [ {b: 1}, {b: 2}, {b: 2} ]

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.6/lodash.min.js"></script>

＆＃13;

然后再说一遍，如果你正在使用lodash，你也可以在最大程度上使用它：

＆＃13;

var myArr = [
  {'a':1},
  {'b':1},
  {'b':2},
  {'a':1},
  {'b':2}
];

var filtered = _.differenceWith(myArr, [{a: 1}], _.isEqual);
console.log(filtered);
// [ {b: 1}, {b: 2}, {b: 2} ]

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.6/lodash.min.js"></script>

＆＃13;

基本上做同样的事情，但更容易阅读。

Answer 2

这对我有用

myArr = [
          {'a':1},
          {'b':1},
          {'b':2},
          {'a':1},
          {'b':2}
        ]

        //Get first item
        for(var key in myArr[0]){
            var firstItem = key;
        }
        alert('First item: ' + firstItem);

        //Remove matches
        var removedItems = []; //Not needed, just used to show you what it's removing.

        myArr.forEach(function(item){
            for (var key in item){
                if(key == firstItem){
                    removedItems.push(key); //Not needed
                    myArr.splice(item, 1); //Remove the array entry
                }
            }
        });
        alert('Removed items: ' + removedItems);

Answer 3

尝试myArr.shift();

它将返回{'a':1}

myArr将为[{'b':1},{'b':2},{'b':2}]

从数组中删除所有特定对象

3 个答案: