引用类型运算符

    let a = {n : 1};
    let b = a;
    a.x = a = {n: 2};


    console.log(a.x) //undefined
    console.log(b.x) //{n:2}

https://blog.csdn.net/Web_J/article/details/107471318

let a={m:10,n:30}
let b=a;
let c=b;
b.m=20;
let d={...b}//相当于Object.assign 第一层对象为深拷贝，再深为浅拷贝
c={n:40}//此时c的地址不再与a,b相同
console.log(a.m) //20
console.log(a===b) //true
console.log(a===c) //false
console.log(b===d) //false（...运算符第一层深拷贝，如果某项还是引用类型会互相影响）
console.log(b===c) //false