Golang: Package, Import
The Main Package
Every Go program is made up of packages.
Programs start running in package named main
, with function main
.
package main import "fmt" func main() { fmt.Println(3 + 4) // 7 }
Every go source code file have the above structure.
Import
import name
-
Import a package named name.
name is a string.
package main import "fmt" import "math" func main() { fmt.Printf("%v\n", math.Sqrt(9)) // 3 }
import (name1; name2; etc)
-
Import multiple packages, with one single import statement.
package main import ( "fmt"; "math" ) func main() { fmt.Printf("%v\n", math.Sqrt(9)) // 3 }
Imported Function Names Begin with Upper Case
Function names from imported packages always start with a Capital letter.
e.g. fmt.Printf
.