问题描述
下面的方法是否是在 Javascript 中深度复制对象的万无一失的方法,即即使对于非常深的嵌套对象/数组?
let newObj = JSON.parse(JSON.stringify(obj));
解决方法
简而言之,这是一个简单但不可靠的深拷贝,适用于简单的 JavaScript 对象。但是对于某些非原始数据类型的属性,它可能会失败。
const set = new Set();
set.add(1);
set.add(2);
const map = new Map();
map.set('Jessie',{phone: "213-555-1234",address: "123 N 1st Ave"})
const obj = {
foo: () => 'bar',date: new Date(),undefined,set,map,}
console.log(obj);
let unreliableNewObj = JSON.parse(JSON.stringify(obj));
console.log(unreliableNewObj); // some properties are lost,some properties are changed like set and map,can compare the result
// ES6 shallow copy that may help
let reliableNewObj = {
...obj,}
console.log(reliableNewObj);
// 'real' deep copy from library
// https://lodash.com/docs#cloneDeep
let deepObj = _.cloneDeep(obj); // if _ is imported
console.log(deepObj)
对于可靠的深层复制,替代方法是: