Guangzhou Huawei Interview Summary

Written questions first

1. The main function of in HTML documents?

Tells the browser's parser what document standard to use to parse this document.

2. Which of the following results is false?Examine == and ===

A.'0' == 0 //true

B.null == undefined //true

C. ' ' == 0 //true

3. Which of the following elements is a block element?Examine inline and block elements

4. Examine JSON.Stringify(obj);JSON.Parse(JSON.stying(obj))

This code const obj = {a:1,b:2}; go through this JSON.stringify(obj);JSON.parse(JSON.stringfy(obj);What is the output after the two processing?

{"a":1,"b":2};{"a":1,"b":2};{a:1,b:2}

5. Examining selector weights

1. !important - - - infinity
2. Inline style - - - 1000
3. id selector - - - 100
4. Attributes, pseudo-classes, classname selectors - - - 10
5. Tag selector - - - 1

6. Which of the following methods can convert the arguments object to an array?

Array.prototype.slice.apply(arguments)

Array.prototype.concat.apply(thisArg,arguments)

Array.from()

7. What is the data storage method that can only be known by manual operation?

localStorage

8. Which of the following statements about closures is incorrect?

Multiple choice

CSS common browser kernel prefixes: -ms-;-moz-;-webkit-;-o-

Browser kernel:IE browser kernel: Trident kernel; Chrome browser kernel: formerly Webkit kernel, now Blink kernel; Firefox browser kernel: Geckokernel, commonly known as the Firefox kernel;

What is the method of Array and String type data in js?

indexOf() ; slice;concat(); includes()

Two calculation questions

The first thing to look at is deep copying.

The second way is to examine the isosceles triangle.