深拷贝

function deepClone(obj={}){
if (typeof obj !== "object" || obj == null) {
// obj是null，或者不是数组对象，直接返回
return obj;
}
// 初始化返回结果
let result;
if (obj instanceof Array) {
result = []
} else {
result = {}
}
 
for (let key in obj){
// 保证key不是原型的属性
if(obj.hasOwnProperty(key)){
// 递归
result[key] = deepClone(obj[key])
}
}
// 返回结果
return result;
}

const obj1 = {
name: ‘ming‘,
address:{
city: ‘beijing‘
},
arr:[1,2,3]
}
const obj2 = deepClone(obj1);
obj2.address.city = ‘hangzhou‘
console.log(obj1.address.city); // beijing