JavaScript最完整的深浅拷贝实现方式详解

let a = 1;
let b = a;
b = 2;
console.log(a);//1
console.log(b);//2

//  concat()
let list = ['a','b','c'];
let list2 = list.concat();
list2.push('d')
console.log(list);//['a','b','c']
console.log(list2);//['a','b','c','d']
//  slice()
let list = ['a','b','c'];
let list2 = list.slice();
list2.push('d')
console.log(list);//['a','b','c']
console.log(list2);//['a','b','c','d']

//二维数组
let list = ['a','b','c',['d','e','f']];
let list2 = list.concat();
list2[3][0] = 'a';
console.log(list);
console.log(list2);

let a = {id:1,name:'a',obj:{id:999}};
let b = new Object();
b.id = a.id;
b.name = a.name;
b.obj = a.obj;
a.name = 'b';
a.obj.id = 888;
console.log(a);
console.log(b);

let a = {id:1,name:'a',obj:{id:999}};
function fun(obj){
    let o = {};
    Object.assign(o,obj);
    return o;
}
let a2 = fun(a);
a2.name ='a2';
a2.obj.id = 888;
console.log(a);
console.log(a2);

let a = {
    name : 'a',
    age : 20,
    obj : {id:999},
    action : function(){
        console.log(this.name);
    }
}
let b = JSON.parse(JSON.stringify(a));
a.name = 'b';
a.obj.id = 888;
console.log(a);
console.log(b);

let a = {
    name:'a',
    skin:["red","blue","yellow",["123","456"]],
    child:{
        work:'none',
        obj:{
            id:999
        }
    },
    action:function(){
        console.log(this.name);
    }
}
//封装的递归方法
    function copyWid(obj){
        let newObj = Array.isArray(obj)?[]:{};
        for (var i in obj){
            if(typeof obj[i] === 'object'){  //判断是不是对象（数组或对象）
               newObj[i] = copyWid(obj[i])  //递归解决多层拷贝
            }else{
                newObj[i] = obj[i]   
            }
        }
        return newObj;
    };
    let b = copyWid(a);
    b.child.obj.id =888;
    b.skin[3][0] = "pink";
    console.log(a);
    console.log(b);

let a = {name:'a',id:99};//如果是数组[xx,xx,xx]，{...a}需要改成[...a]
let b ={...a};  //[...a]
a.id =88;
console.log(a);
console.log(b);