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
See also : Golang : Connect to database (MySQL/MariaDB) server
By Adam Ng
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