The difference between deep copy and shallow copy in JS

It mainly depends on whether the copied new object and the original object will interact , Change one , Will the other change

difference

1） Shallow copy ： It just points to the copied memory address , If the original address changes , Then the shallow copied objects will change accordingly
2） Deep copy ： Create a new address in memory to store the copied object , Old and new objects do not share memory , Modify one of , The other will also be affected

Method

1） Shallow copy

• adopt = Direct assignment
• Object.assign（ Target audience , Source object ） Method

2） Deep copy

• adopt JSON Object to implement deep copy ：
  *1----JSON.stringify： take js Value （ Object or array ） Turn to one JSON character string
  *2----JSON.parse： Used to resolve JSON character string , Convert to Object type

        var obj={
    name:'jack',age:18}
        var obj1=JSON.parse(JSON.stringify(obj))
        obj1.age=20
        console.log(obj);//{name:'jack',age:18}
        console.log(obj1);//{nmae:'jack',age:20}

• Using extension operators for deep copy

        var obj={
    name:'bob',age:10}
        var obj1={
    ...obj,age:20}
        console.log(obj1);//{name:'bob',age:20}