### 1.2 Notes
** ** Role: add some description and explanation in the code, to facilitate their other programmers or programmers reading the code
** ** two formats
1. Single-line comments ** **: // description information
- usually on the top of a line of code, or at the end of a sentence, the line described == ==
2 ** ** multi-line comments: / * Description information * /
- usually on the top of a piece of code, do == == overall description of the sections of the code
> Tip: the compiler when compiling code, will ignore the content of the comment
