Initial Research on JS (1) and variable types, operators, common functions and conversions

As a name. NET background developers are taking the test to transform to Web Front-end development. They have also written a generation of front-end code before. However, when looking back at JS and turning to it, they suddenly find that: originally, JS is not that simple. I have not noticed many details before. Now I want to record the learning knowledge points as study notes, so I can take a look at them from time to time. If there are any errors, please read the official comments and correct them. JavaScript is a lightweight scripting language for Web programming. It is often referred to as JavaScript. It is widely used in PCs and various mobile devices. It is often used together with HTML and CSS to form webpage pages. It is also often associated with some people and Java, but in essence they are completely two different programming languages (when I met this problem, I believe someone actually thinks so ). JavaScript execution requires an interpreter ("engine") as part of the browser. This chapter includes: 1. JS reference and comment; 2. Variables and data types 3. Operators and expressions 4. Common Function objects 5. type conversion before writing: debugging is an important task of writing a program. In this series, all debugging is performed using the Chrome browser. The operation is as follows: Open the browser, press "F12", go to the "Control" tab, and enter the code in the input column. For JS Code debugging on the HTML page, go to the "Source" tab and place the breakpoint where necessary. 1. JavaScript references and comments 1.1 References 1) Written In The