Go MongoDB

Connect your Go applications to MongoDB

Installing the MongoDB Go Driver


Go My Go Tutorial

Go Online Book (Free)

Go My Go Tutorial

Go (1.15.6 or later) Installation and Setup in Windows 10 (Fresh Install)

Official Go download page, this link gives you more option to choose from OS platform and OS architecture x86-64 build. And you can use the go build command parameter to building a binary for an application that can run for CPU of x86 (386) and x86-64.


Open the MSI file you downloaded and follow the prompts to install Go. The default folder used is C:/go. Or choose any folder that Windows 10 security may not ask for an administrator password for install programs/files using that folder path.

System Environment variable created by MSI installer

GOPATH C:\Users\loginname\go

Note: loginname is the user name to Window login

PATH C:\Go\bin


Launch a windows terminal, type go version

go version go1.15.6 windows/amd64 output confirmed go installation has been successful. Otherwise, use the Windows Control panel app -> Programs find go1.15.6 has been program has been installed.


Google, Go forum, and Stackoverflow for assistance.

Go My Go Tutorial

Range Over Slice and Map

package main

import "fmt"

func main() {
  kvs := map[string]string{"1":"shan kuo","2":"Hoi Leng","3":"Choi Yan","4":"Evelyn Chan"}
  for k, v := range kvs {
    fmt.Printf("%s -> %s\n",k,v)

 go build
 ./main
1 -> shan kuo
2 -> Hoi Leng
3 -> Choi Yan
4 -> Evelyn Chan

Go My Go Tutorial

Looping Over Arrays and Slices

package main

import "fmt"

func main() {
  names := []string{"Shank Kuo","Hoi Leng","Choi Yan","Evelyn Chan"}

  for i:=0; i < len(names); i++ {

go version go1.14 linux/amd64
 go run main.go
Shank Kuo
Hoi Leng
Choi Yan
Evelyn Chan

Go Testing

Go Built-in Unit Testing

Naming conventions ( prefix with underscore)

suffix with underscore with the filename. For example, the hello.go is the source file then hello.go with test package will have the filename hello_test.go tells the go test command that this file contains test functions.


Testing package

Importing the testing package is a must to be included along with other imported packages such as the “fmt” package that it commonly in use.

import (

Test command

At the command line where the source code directory, run the go test command to execute the test

go test

Implement a Test Functions

Expect results of the function

Prefix the Test to the function name. For example, TestHelloName()

// TestHelloName calls greetings.Hello with a name, checking 
// for a valid return value.
func TestHelloName(t *testing.T) {
    name := "Gladys"
    want := regexp.MustCompile(`\b`+name+`\b`)
    msg, err := Hello("Gladys")
    if !want.MatchString(msg) || err != nil {
        t.Fatalf(`Hello("Gladys") = %q, %v, want match for %#q, nil`, msg, err, want)


Go Graphic Library My Go Tutorial

Fyne Cross-Platform GUI

Fyne is an easy to use UI toolkit and app API written in Go. It is designed to build applications that run on desktop and mobile devices with a single codebase.

Setup the Fyne development environment

  • Go compiler installed and setup (1.16)
  • IDE – Visual Studio Code
  • C compiler installed (MSYS2 MinGW 64-bit)
  • Git Fyne

C compiler installation with MSYS2 MinGW 64-bit

The steps for installing with MSYS2 (recommended) are as follows:

  • Install MSYS2 from
  • Once installed do not use the MSYS terminal that opens
  • Open “MSYS2 MinGW 64-bit” from the start menu
  • Execute the following commands:

$ pacman -Syu

$ pacman -S git mingw-w64-x86_64-toolchain

go get