Object.assign 和 b = {...a} 是深拷贝还是浅拷贝？

• 第一级是深拷贝，以后各级是浅拷贝
• B复制A —— A变B变，浅拷贝 ；A变B不变，深拷贝

第一级是深拷贝：
let a = {James: {age: 18}}
let b = Object.assign({}, a)
b.James = 20
console.log(b) // { James: 20 } 
console.log(a) // { James: { age: 18 } } 
复制代码

以后各级是浅拷贝：
let a = {James: {age: 18}}
let b = Object.assign({}, a)
b.James.age = 20
console.log(b) // { James: { age: 20 } } 
console.log(a) // { James: { age: 20 } } 
复制代码

转载于:https://juejin.im/post/5d085f62f265da1b5f265767