Go — Get Started

Installation

Download Go from go.dev/dl:

# Verify installation
go version
# go version go1.22.0 linux/amd64

# Check Go environment
go env

Creating a module

# Create a new directory
mkdir myproject
cd myproject

# Initialize a module
go mod init myproject

# This creates go.mod:
# module myproject
# go 1.22

Your first program

Create main.go:

package main

import "fmt"

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

Running the program

# Run directly
go run main.go

# Build a binary
go build -o myapp main.go
./myapp

Project structure

myproject/
├── main.go
├── go.mod
├── go.sum          # Dependencies (auto-generated)
├── cmd/            # Executable entry points
│   └── server/
│       └── main.go
├── internal/       # Private packages
│   └── handler/
│       └── handler.go
├── pkg/            # Public packages
│   └── utils/
│       └── utils.go
└── README.md

Adding dependencies

# Add a dependency
go get github.com/gin-gonic/gin

# Update dependencies
go get -u ./...

# Tidy (remove unused)
go mod tidy

# Download all dependencies
go mod download

Running tests

// main_test.go
package main

import "testing"

func TestAdd(t *testing.T) {
    result := add(2, 3)
    if result != 5 {
        t.Errorf("add(2, 3) = %d; want 5", result)
    }
}

# Run tests
go test

# Run with verbose output
go test -v

# Run specific test
go test -run TestAdd

# Test coverage
go test -cover

Build for different platforms

# Linux
GOOS=linux GOARCH=amd64 go build -o myapp-linux

# macOS
GOOS=darwin GOARCH=arm64 go build -o myapp-mac

# Windows
GOOS=windows GOARCH=amd64 go build -o myapp.exe

Useful commands

Command	Description
go run	Run a program
go build	Compile a binary
go test	Run tests
go fmt	Format code
go vet	Static analysis
go mod init	Initialize module
go get	Add dependency
go doc	Show documentation

IDE setup

Recommended editors:

• VS Code with Go extension
• GoLand by JetBrains
• Vim with vim-go plugin

Mini Practice

1. Initialize a Go module and create main.go
2. Run the program with go run
3. Build a binary with go build
4. Add a test file and run go test

Up Next

In the next lesson, you'll learn about Syntax — Go's basic syntax and conventions.