[Yugong series] go teaching course in July 2022 004 go code Notes

Preface

1. The definition of annotation

Annotation is the interpretation and explanation of the code . The purpose is to make it easy for others and themselves to understand , You can see at a glance what this code is for . Correct program annotation generally includes preamble annotation and functional annotation . The main content of the preamble note includes the interface of the module 、 Description of data and function of modules . The main content of the functional annotation of the module includes the function of the program segment 、 The function of the statement and the state of the data .

2. The function of annotation

Comments are just for readability , Will not be compiled by the computer .

One 、Go code annotation

Go Language annotations are mainly divided into two categories , These are single line comments and multi line comments .

1. Single-line comments

Single line notes are abbreviated as line notes , Is the most common form of annotation , Can be used anywhere to

//

The opening single line comment ;

Shortcut key ：ctrl+c

// Add  Addition of two numbers （ This line will be intercepted as a brief introduction ）
//  Precautions and principle of adding two numbers （ This line is a super detailed introduction ）
func Add(n1,n2 int)int{
 return n1+n2
}


2. Multiline comment

Multiline annotation is abbreviated as block annotation , With

/*

start , And

*/

ending , And it can't be nested , Multiline annotations are generally used for package document description or block code fragments .

Shortcut key ：shift+ctrl+c

/*
regexp  The package implements a simple library for regular expressions .

The regular expression syntax accepted by the library is ：

 regexp:
 concatenation { '|' concatenation }
 concatenation:
 { closure }
 closure:
 term [ '*' | '+' | '?' ]
 term:
 '^'
 '$'
 '.'
 character
 '[' [ '^' ] character-ranges ']'
 '(' regexp ')'
*/
package regexp


summary

The function of annotation in the program is to annotate and explain the program , Easy to read the source code . The compilation system will automatically ignore the comments when compiling the source code , Therefore, annotations have no effect on the function realization of the program . Add appropriate comments to the source code , It can improve the readability of the source code .