Golang : The Tao of importing package

Jotting down this quick tutorial on how to use import statement properly with formatted I/O - fmt package. However, this example can be applied to all Golang packages. Hope this simple tutorial can be useful to you too.

The standard way to import package in Golang.

import "fmt"

 package main

 import "fmt"

 func main() {
  fmt.Println("Hello, playground")
 }

In case, you want to name the package name differently or want to use a shorter name to invoke the package.

import ftio "fmt"

 package main

 import ftio "fmt"

 func main() {
  ftio.Println("Hello, playground")
 }

If the program is a short and simple program. Use a period . to represent a package. Useful in a situation where there are a lot of invocation of the package functions. However, this might cause readability issue later on...so use it with care.

import . "fmt"

 package main

 import . "fmt"

 func main() {
  Println("Hello, playground")
 }

Lastly, the underscore _ is used in import statement to initialize a package. Without the underscore _ , you will get imported but not used error message

import _ "fmt" -- initialize for other function to use.

 package main

 import _ "fmt"

 func main() {
  Println("Hello, playground") // will cause prog.go:6: undefined: Println error
 }

a common example to use underscore is to initialize the mysql driver in order to the sql.Open() function to use the mysql driver. See full example at :

https://www.socketloop.com/tutorials/golang-connect-to-database-mysql-mariadb-server

Happy Coding!

Reference:

https://www.socketloop.com/tutorials/golang-shortening-import-identifier