文章目录

• • 浅拷贝
  • • Object.assign
  • 深拷贝
  • • JSON
    • 第三方库lodash
    • 手写一个深拷贝

浅拷贝

Object.assign

let Person = {
    name: '123',
    arr:[1,2,3]
}
var person = {}

// 对于引用类型只是浅拷贝
Object.assign(person, Person) //浅拷贝

person.name = "111"
person.arr.push(456)

console.log(person === Person) //false
console.log(person.name) //111
console.log(Person.name) //123      // 没同步
console.log(Person.arr);    // [ 1, 2, 3, 456 ]  同步了

深拷贝

JSON

  obj = {
            name: "tom",
            id: 18,
            goods: {
                id: 123
            },
            list: [1, 23, 1, 4]
        }

        function deepClone(obj) {
            let result = JSON.parse(JSON.stringify(obj));
            return result;
        }

        console.log(deepClone(obj))

存在问题 无法拷贝function undefined

第三方库lodash

参考链接

手写一个深拷贝

let obj = {
    name: '123',
    arr: [1, 2, 3],
    userdata: {
        likes: ["玩", "ci"]
    }
}
function deepCopy(obj){
    let objClone = Array.isArray(obj)?[]:{};
    if(obj && typeof obj =="object"){
        for(key in obj){
            if(typeof obj[key]=="object"){
                objClone[key]=deepCopy(obj[key])
            }else{
                objClone[key] = obj[key]
            }
        }
    }
    return objClone;
}

let newObj=deepCopy(obj)

newObj.userdata.likes.push("456")
newObj.userdata.likes[0]="和"

console.log(newObj,obj);