Creating new Go packages
1、创建一个Go package，叫： MyLib
• Let’s create a Go package called MyLib and use it in our program
2、在go_project文件夹下开启终端，输入指令创建go.mod文件。
go mod init go_project
• Assuming our program resides in go_project/, then type “go mod init go_project” to create a go.mod file
• The go.mod file tells Go that go_project is a module (a module contains one or more packages) – and that our new package can be found in the current directory
3、创建一个目录，叫：MyLib
• Next, create a directory named MyLib
4、在这个目录下，创建文件，叫：Lib1.go
• In MyLib directory, create a file named Lib1.go
Using our Go packages
5、导入MyLib到我们的程序
• Import MyLib into our program
6、调用MyLib中的方法
• Call the method(s) in MyLib
Visibility in Go packages
• A package 是最小的单位 of private encapsulation（私有封装） in Go
• All identifiers defined within a package are visible within the
package
• When a package is being imported, only its exported identifiers
can be accessed
• An identifier is exported if it begins with a Capital letter
Package (Example)
#参考网站
https://go.dev/tour/list
https://www.golang-book.com/books/intro
https://yourbasic.org/golang/
https://www.digitalocean.com/community/tutorials/how-to-use-go-modules
https://github.com/golang/tools/blob/master/gopls/doc/workspace.md