记一次前端笔试

今天晚上听完宣讲，顺便做了套前端开发的题。好多不会啊。。。

顺手记下一点我记得的吧

1.

typeof(null)

typeof(undefined)

typeof(Object)

2.

function ff(){
console.log(a);
console.log(foo());
var a=1;
function foo(){
console.log(a++);
}

what is the output?

3. 

function interval(){

<span style="white-space:pre"></span>interval(vvv,10);,10}

function  interval(vvv,10);

difference?

4. px em rem :difference?

5. name some vmc or vmmc model and compare them.

6. cookie sessionStorage localStorage :difference?

7. <div style="display:none">

<span style="white-space:pre"></span><img imgsrc="img.jpg" alt="photo">

   <div>

问是否会发送http请求

8. 响应式页面是什么意思，如何实现

9. 某app站点会有大量图片资源，如何给用户提供更好的体验？

暂时只记得这些了，3只记得大意