本文实例讲述了JS 数组和对象的深拷贝操作。分享给大家供大家参考，具体如下：
一.数组的深拷贝
let arr = [
undefined,
function(){
console.log(123);
},
true,
null,
{
name:"123",
age:23
}
];
// arr作为拷贝对象1. Array.from()
Array.from()能将一个类数组转化成一个真正的数组，因此它返回的是一个新数组。
let arr1 = Array.from(arr);
arr[0] = 2;
console.log(arr1);
// [ undefined, [Function], true, null, { name: '123', age: 23 } ]2. Object.assign()
let arr1 = Object.assign([], arr)
arr[0] = 2;
console.log(arr1);
// [ undefined, [Function], true, null, { name: '123', age: 23 } ]此方法也可用作对象的深拷贝
3. Slice()
let arr1 = arr.slice(0);
arr[0] = 2;
console.log(arr1);
// [ undefined, [Function], true, null, { name: '123', age: 23 } ]4. Concat()
let arr1 = arr.concat();
arr[0] = 2;
console.log(arr1);
// [ undefined, [Function], true, null, { name: '123', age: 23 } ]5. 扩展运算符深拷贝
// let [...arr1] = arr; // 这两种都可以
let arr1 = [...arr];
arr[0] = 2;
console.log(arr1);
// [ undefined, [Function], true, null, { name: '123', age: 23 } ]此方法也可用作对象的深拷贝
二.对象的深拷贝
let obj = {
name: "a",
age: 20,
sex: false,
user: {
a: 20,
n: "b"
},
f: function(){
return 1;
},
u: undefined,
n: null
}用扩展运算符和Object.assign()方法可以深拷贝对象
let obj1 = Object.assign({}, obj)
obj[age] = 2;
console.log(obj1);
// let obj = { name: "a", age: 20, sex: false,user: {a: 20,n: "b},f: function(){return 1;},u: undefined,n: null}相关学习推荐：javascript视频教程
