1. Count the number of occurrences of each character in a string

2. Sort the array in ascending order according to price, and in descending order according to comment when price is the same

[{
    name:'chop',
    price:'24',
    comment:'2'
},{
    name:'row',
    price:'23',
    comment:'2'
},{
    name:'bone',
    price:'23',
    comment:'3'
}]
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3. Hot update principle

4. What functions does Webpack have? 1> Compress files 2> pack javascript modules 3> Pack static resources 4> Webpack-dev-server: It listens to files and automatically compilers and refreshes browser pages after the files are modified.

5. How to optimize the CSS? Sprite diagram (also called CSS Sprite) Sprite diagram explanation

6. How to achieve the five-pointed star display 0.3,0.5,0.6 CSS

// Float the yellow star above the white star, and control the width of the yellow star to achieve the proportion of yellow in the star. <body> <div class="one"></div>
  <div class="two"></div>
</body>
<style media="screen">
  .two{
    width: 30px;
    height: 30px;
    background: url(./badStar.png);
  }
.one{
  float: left;
  width: 18px;
  height: 30px;
  background: url(./star.png);
}
</style>
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7. How to implement mask layer

8. Small program project related

9. Functions and benefits of the KOA Onion model

Content-type: “Application /x-www-form-urlencoded”

11. The cookie and session

12. Reverse proxy and forward proxy

13. Vuex workflow

14. Prototype and closure related issues

15. What are the advantages of applets over web pages

16.axios

17. Get, post, put

18. Comma operator

19. Git conflict handling

20. How to use CSS to make ellipses when there is too much content

<div class="title"< div> <style media= < span style = "box-sizing: border-box! Important; word-wrap: break-word! Important"screen"> .title{ width:300px; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; } </style>Copy the code

21. Vux synchronization asynchronous problem