Object.assign覆盖原始引用？

Question

我试图用Object.assign()“合并”两个对象，但不知何故原始对象被覆盖。见例如：

var x = {x:1}; 
 
var y = {y:2}; 
 

 
var z = Object.assign(x, y); 
 

 
// what I've expected 
 
console.log(z); // {"x": 1, "y": 2} 
 

 
// what I haven't expected 
 
console.log(x); // {"x": 1, "y": 2}

Answer 1

一个空的对象必须为Object.assign为新的合并对象的第一个参数被创建来提供。

var x = { 
 
    x: 1 
 
}; 
 
var y = { 
 
    y: 2 
 
}; 
 

 
var z = Object.assign({}, x, y); 
 

 
// new object 
 
console.log(z); // {"x": 1, "y": 2} 
 

 
// still the same 
 
console.log(x); // {"x": 1} 
 
console.log(y); // {"y": 2}

You can read more information about Object.assign here.

Answer 2

您需要更改像下面

var z = Object.assign({},x, y); 

这里是工作的jsfiddle：https://jsfiddle.net/ht7jumh6/

Answer 3

传递一个空{}到assign()作为第一参数。

var x = {x:1}; 
 
var y = {y:2}; 
 

 
var z = Object.assign({},x, y); 
 

 
console.log(z); // {"x": 1, "y": 2} 
 

 
console.log(x); // {"x": 1}