Golang packages

Imports

import "fmt"

import (
    "fmt"                                // builtin pkgs have no module-path prefix
    "golang.org/x/example/stringutil"    // third-party pkgs have module-path prefix
)

Defining Packages

# project heirarchy
myproject/
    mypackage/
        libfoo.go
        libbar.go
    main.go
    go.mod

myproject/go.mod

// go.mod

module github.com/you/myproject

go 1.18

myproject/main.go

// main.go

package main

import "github.com/you/myproject/mypackage"

func main() {
    mypackage.PrintHi();
}

myproject/mypackage/libfoo.go

// mypackage/libfoo.go

package mypackage

import "fmt"

func PrintHi() {
    fmt.Println("hi")
}