写法一：
//深拷贝
const deepCopy = (data) => {
if (typeof data != ‘object‘ || data == null) return data
let result = null
if (data instanceof Array) {
//Array的原型是Object
result = []
} else {
result = {}
}
for (let key in data) {
const one = data[key]
result[key] = deepCopy(one)
}
return result
}
写法二：JSON.parse(JSON.stringify(data))
原因是如何data内有特殊的对象，例如Date类型的数据会被转成字符串，RegExp被转成{}，Error被转成{}
let b = {
g: ‘i am g‘,
e: new Error(‘我是错误‘)，
exp:new RegExp(/ab+c/, ‘g‘),
time: new Date()
}
let c = JSON.parse(JSON.stringify(b))
console.log(c.time instanceof String) //true
console.log(c.exp) //{}
console.log(c.e) //{}
原文：https://www.cnblogs.com/baixinL/p/14922204.html