JavaScript authoritative Guide chapter II-lexical structure-the Book of Reading

1.JavaScript is written in the Unicode character set. The Unicode character set is intended for cross-language, cross-platform communication, which corresponds to one by one of all used text symbols to the computer's binary.

2.JavaScript is case-sensitive. HTML is case-insensitive. A special example of this is that the onclick event written in the HTML tag can be written as an onclick, and can only be written in lowercase when JavaScript writes the Click event.

3. If you are using a computer that cannot enter a character, you can use a notation provided in JavaScript, which is \u+4 a hexadecimal number.

4. Comments with//or/**/

5. Direct volume. Is the data value that is used directly in the program.

6. The identifier. This is where the programmer needs to pick up the name in the program itself.

7. Keywords. Is the word that JavaScript keeps for itself.  

In addition, each particular JavaScript runtime environment has its own unique list of global variables and functions, preferably not as its own variable name and function name.

If I enter a in VS, I'm going to show you a lot of pre-defined variables and functions.

8. Optional semicolon. Plus a semicolon. Make it easy for you to read.

JavaScript authoritative Guide chapter II-lexical structure-the Book of Reading