我迟到回答这个问题,但我有另一种方式来克隆对象:

function cloneObject(obj) {
    if (obj === null || typeof(obj) !== 'object')
        return obj;
    var temp = obj.constructor(); // changed
    for (var key in obj) {
        if (Object.prototype.hasOwnProperty.call(obj, key)) {
            obj['isActiveClone'] = null;
            temp[key] = cloneObject(obj[key]);
            delete obj['isActiveClone'];
        }
    }
    return temp;
}

var b = cloneObject({"a":1,"b":2});   // calling

更快、更快的是:

var a = {"a":1,"b":2};
var b = JSON.parse(JSON.stringify(a));  

和

var a = {"a":1,"b":2};

// Deep copy
var newObject = jQuery.extend(true, {}, a);

我已经标记了代码,你可以在这里测试结果:

和分享结果: 参考: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty

单线 ECMAScript 6 解决方案(特殊对象类型如 Date/Regex 未处理):

const clone = (o) => typeof o === 'object' && o!== null? // only clone objects (Array.isArray(o)? // if cloning an array o.map(e => clone(e)) : // clone each of its elements Object.keys(o).reduce( // otherwise reduce every key in the object (r, k) => (r[k] = clone(o[k]), r), {} // and save its cloned value

如果您正在使用它,UnderScore.js图书馆有一个克隆方法。

var newObject = _.clone(oldObject);

Lodash 有一个可爱的 _.cloneDeep(值) 方法:

var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// => false

由于这个问题有很多注意力和答案,参考内置的功能,如 Object.assign 或自定义代码到深克隆,我想分享一些图书馆到深克隆,

1、斯克隆

npm 安装 --savedev esclone https://www.npmjs.com/package/esclone

在 ES6 中使用例子:

import esclone from "esclone";

const rockysGrandFather = {
  name: "Rockys grand father",
  father: "Don't know :("
};
const rockysFather = {
  name: "Rockys Father",
  father: rockysGrandFather
};

const rocky = {
  name: "Rocky",
  father: rockysFather
};

const rockyClone = esclone(rocky);

在 ES5 中使用例子:

var esclone = require("esclone")
var foo = new String("abcd")
var fooClone = esclone.default(foo)
console.log(fooClone)
console.log(foo === fooClone)

二、深度复制

npm 安装深复制 https://www.npmjs.com/package/deep-copy

例子:

var dcopy = require('deep-copy')

// deep copy object 
var copy = dcopy({a: {b: [{c: 5}]}})

// deep copy array 
var copy = dcopy([1, 2, {a: {b: 5}}])

3、克隆深度

$ npm 安装 --save clone-deep https://www.npmjs.com/package/clone-deep

例子:

var cloneDeep = require('clone-deep');

var obj = {a: 'b'};
var arr = [obj];

var copy = cloneDeep(arr);
obj.c = 'd';

console.log(copy);
//=> [{a: 'b'}] 

console.log(arr);

使用今天的JavaScript来克隆一个对象:ECMAScript 2015(以前被称为ECMAScript 6)

var original = {a: 1};

// Method 1: New object with original assigned.
var copy1 = Object.assign({}, original);

// Method 2: New object with spread operator assignment.
var copy2 = {...original};

旧浏览器可能不支持 ECMAScript 2015. 一个常见的解决方案是使用 JavaScript-to-JavaScript 编译器,如 Babel 发行您的 JavaScript 代码的 ECMAScript 5 版本。

正如 @jim-hall 指出的那样,这只是一个微小的副本. 属性属性被复制为参考:更改一个将改变另一个对象/实例的值。