Front-end must know--JavaScript basics 3 parts

　

Why learn JavaScript?

JavaScript is one of 3 languages ​​that web developers must learn:

1. HTML  defines the content of a web page
2. CSS  describes the layout of a web page
3. JavaScript  controls the behavior of web pages

　You must know the basics, you can say is must memorize. Or else? The foundation is solid, and the high-rise buildings behind it are flat, and this flat ground is the most basic knowledge point for development.　

　Since you choose to do this, you must know the front-end knowledge points!　

 　Document Object Model