的JavaScript - 過濾掉兩個數組，並採取了愚弄

Question

比方說，我有兩個數組：

var sellersDatabase = [ 
    { name: 'Mark', start_date: '2017-06-27' }, 
    { name: 'Jane', start_date: '2017-06-27' } 
]; 

var sellersAPICall = [ 
    { name: 'Mark', start_date: '2017-06-27' }, 
    { name: 'Joe', start_date: '2017-06-22' }, 
    { name: 'Steven', start_date: '2017-04-11' }, 
    { name: 'Jane', start_date: '2017-06-27' } 
]; 

會如何，無論是使用ES6或Lodash，讓那些不包含在第一陣列中的區別？是的，我試過lodash的difference()。

所以，我期望的輸出將是：

var toInsertIntoDB = [ 
    { name: 'Joe', start_date: '2017-06-22' }, 
    { name: 'Steven', start_date: '2017-04-11' } 
]; 

---

這樣做：

javascript const toInsertToDB = _.difference(sellersDatabase, sellersAPICall); console.log(toInsertToDB);

輸出：

[{ "name": "Mark", "start_date": "2017-06-27" }, { "name": "Jane", "start_date": "2017-06-27" }]

（當我想要相反）

Answer 1

由於您正在比較對象數組，而不是基元，請使用_.differenceBy()，以及應通過哪種屬性比較對象。另外，sellersAPICall數組應該是第一個（參考數組）。

var sellersDatabase = [ 
 
    { name: 'Mark', start_date: '2017-06-27' }, 
 
    { name: 'Jane', start_date: '2017-06-27' } 
 
]; 
 

 
var sellersAPICall = [ 
 
    { name: 'Mark', start_date: '2017-06-27' }, 
 
    { name: 'Joe', start_date: '2017-06-22' }, 
 
    { name: 'Steven', start_date: '2017-04-11' }, 
 
    { name: 'Jane', start_date: '2017-06-27' } 
 
]; 
 

 
var result = _.differenceBy(sellersAPICall, sellersDatabase, 'name'); 
 

 
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

如果你想比較2個屬性，你可以使用串接兩個值的回調函數：

var sellersDatabase = [ 
 
    { name: 'Mark', start_date: '2017-06-27' }, 
 
    { name: 'Jane', start_date: '2017-06-27' } 
 
]; 
 

 
var sellersAPICall = [ 
 
    { name: 'Mark', start_date: '2017-06-27' }, 
 
    { name: 'Joe', start_date: '2017-06-22' }, 
 
    { name: 'Steven', start_date: '2017-04-11' }, 
 
    { name: 'Jane', start_date: '2017-06-27' } 
 
]; 
 

 
var result = _.differenceBy(sellersAPICall, sellersDatabase, function(o) { 
 
    return o.name + '-' + o.start_date; 
 
}); 
 

 
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>