【拼多多】前端实习一面

4.20一面

function Foo() {
            Foo.a = function () {
                console.log(1)
            }
            this.a = function () {
                console.log(2)
            }
        }
        Foo.a = function () {
            console.log(4)
        }
        Foo.a() //4
        let obj = new Foo();
        Foo.prototype.a = function () {
            console.log(3)
        }
        obj.a() //2
        Foo.a()//1

async function async1() {
            console.log('async1 start')
            await async2()
            console.log('async1 end')
        }
        async function async2() {
            console.log('async2')
        }
        console.log('script start')
        setTimeout(function () {
            console.log('setTimeout')
        }, 8)
        async1()
        Promise.resolve(1)
            .then(res => {
                console.log('promise1', res)
            })
            .then(res => {
                console.log('promise2', res)
                return Promise.reject(1)
            })
            .then(res => {
                console.log('promise3', res)
            })
            .catch(e => {
                console.log('promise4', e)
            })
            .then(res => {
                console.log('promises', res)
            })
        console.log('script end')

        // script start
        // async1 start 
        // async2
        // script end⭐ 
        // async1 end
        // promise1 1
        // promise2 undefined 
        // promise4 1
        // promise5 undefined  ⭐catch后仍有输出
        // setTimeout

1. 如何理解SPA，SPA缺点是什么
2. Vue这些框架相比于jquery这些优点是什么，你怎么理解MVVM
3. vue中的key作用是什么，好处是什么，不用key会发生什么
4. 防抖节流
5. 说说路由懒加载
6. 懒加载是针对的是路由还是组件？答路由(页面❌)，面试官纠正说是组件
7. 说说elementUI，理解它的原理吗❌
8. 算法题：leetcode原题：有效的括号（https://leetcode-cn.com/problems/valid-parentheses/）+ 两数之和（https://leetcode-cn.com/problems/two-sum/）