最简单的实现

不足之处：JSON会过滤掉function、undefined、null

var newObj = JSON.parse(JSON.stringify(obj))

deepClone

递归实现

function deepCoty(obj){
    if(typeof obj == "object"){
        var result = Array.isArray(obj) ? [] : {}
        for(let i in obj){
            result[i] = obj[i] == null ? null :
                typeof obj[i] == "object" ? deepCoty(obj[i]) : obj[i]
        }
    }else{
        var result = obj
    }
    return result
}

测试：

var obj = "test1"
var obj1 = [1,3,4,"5"]
var obj2 = {
    string: "string--",
    array: [1,2,3,{name: "xiaoming"}],
    people: {
        name: "xiaoming",
        age: 11
    },
    no: null
}

console.log(deepCoty(obj))
console.log(deepCoty(obj1))
console.log(deepCoty(obj2))