Shulou(Shulou.com)06/03 Report--

This article will explain in detail what are the technical points when learning Web front-end development, and the content of the article is of high quality, so the editor will share it with you for reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

Now more and more people are learning the front end, and the quality of learning is uneven. The identity of people from the past tells you that if you haven't made up your mind to spend time learning Web front-end, you can also find some video to learn what common technical points are there in Web front-end development! Next, take a look at the common technical points of Web front-end development!

1. What performance optimization methods do you have?

(1) reduce the number of http requests: CSSSprites,JS, CSS source code compression, image size control is appropriate; web Gzip,CDN hosting, data cache, picture server.

(2) JS+ data of the front-end template to reduce the bandwidth waste caused by HTML tags. The front-end uses variables to save the results of AJAX requests. Each time the local variables are operated without requests, the number of requests is reduced.

(3) innerHTML is used instead of DOM operation to reduce the number of DOM operations and optimize javascript performance.

(4) when there are a lot of styles to be set, set className instead of directly manipulating style.

(5) use less global variables and cache the results of DOM node search. Reduce IO read operations.

(6) avoid using CSS_Expression (css expression), also known as Dynamicproperties (dynamic attribute).

(7) preload the picture, put the stylesheet at the top and the script at the bottom with a timestamp.

2. What is elegant demotion?

Elegant downgrade: Web sites work in all newer browsers, and if users are using older browsers, the code checks to see if they work. Due to the unique box model layout problem of IE, the hack practice for different versions of IE has been gracefully degraded, adding candidates for browsers that do not support features, so that the experience of some form of degradation on older browsers will not fail completely.

3. What is progressive enhancement

Progressive enhancement: start with the basic features supported by all browsers, gradually add features that are supported only by newer browsers, and add additional styles and features that are harmless to the underlying browser. When browsers support them, they are automatically rendered and functioning.

In fact, for the technical position of the web front-end, it needs more practical experience of the project than the theory on paper.

On learning Web front-end development of which technical points to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.