面试题第一弹之JS基础(2019/10/30)

第一题 合并

1 const a = {
2     name: "zhangsan",
3     age: 22
4 }
5 
6 const b = {
7     name: "lisi",
8     age: 55
9 }

a，b对象，并且不改变a，b，把合并后的对象转为字符串打印到控制台

答案: 

var c = {}
c.a = JSON.parse(JSON.stringify(a));
c.b = JSON.parse(JSON.stringify(b));
var string = "";
function fn(object) {
    for (const key in object) {
        if (object.hasOwnProperty(key)) {
            const element = object[key];
            if(typeof element == "object"){
                fn(element);
            }else {
                string += "," + key + ":" + element 
            }
        }
    }
}

fn(c);
console.log(string.slice(1))

 第二题 把setTimeout(()=>{return 3+4;})封装在Promise中并获得其值

1 new Promise((resolve, reject) => {
2     setTimeout(() => {
3         resolve(3 + 4);
4     })
5 }).then((data) => {
6     console.log(data)
7 })