Getting Started with Go

Why Learn Go?

Go sits in a sweet spot: it's as fast as C/C++ for most workloads, but as easy to write as Python. It compiles to a single binary with no dependencies, making deployment trivial. Its built-in concurrency model (goroutines and channels) makes it perfect for servers, APIs, and distributed systems.

Installing Go

Go has a simple installation process. Download the binary, add it to your PATH, and you're ready.

macOS

# Using Homebrew
brew install go

# Verify
go version

go version go1.22.2 darwin/arm64

Linux

# Download and extract
wget https://go.dev/dl/go1.22.2.linux-amd64.tar.gz
sudo tar -C /usr/local -xzf go1.22.2.linux-amd64.tar.gz

# Add to PATH (add to ~/.bashrc or ~/.zshrc)
export PATH=$PATH:/usr/local/go/bin

go version

Windows

Download the MSI installer from go.dev/dl and run it. Go is automatically added to PATH.

Your First Go Program

Let's create the classic "Hello, World!" but with a twist — we'll also demonstrate Go's strict typing and formatting.

Create a Module

Every Go project starts with a module. A module is a collection of packages with a go.mod file:

mkdir hello && cd hello
go mod init hello

Write main.go

package main

import "fmt"

func main() {
    // Variables with type inference
    name := "Gopher"
    age := 1

    // Formatted output
    fmt.Printf("Hello, %s! You are %d day(s) into Go.\n", name, age)

    // Multiple return values (a Go specialty)
    sum, product := calculate(3, 4)
    fmt.Printf("3+4=%d, 3*4=%d\n", sum, product)
}

func calculate(a, b int) (int, int) {
    return a + b, a * b
}

go run main.go

Hello, Gopher! You are 1 day(s) into Go.
3+4=7, 3*4=12

Key things to notice: package main and func main() are the entry point. := declares and assigns a variable with type inference. Functions can return multiple values. Unused imports and variables are compile errors — Go enforces clean code.

Go Modules

Go modules manage dependencies. The go.mod file tracks your module name and dependency versions:

# Initialize a module
go mod init github.com/yourname/myproject

# Add a dependency (automatically when you import it)
go get github.com/gin-gonic/gin

# Tidy up (remove unused, add missing)
go mod tidy

# View dependencies
cat go.mod

IDE Setup

# Format your code (Go has ONE standard style)
go fmt ./...

# Run tests
go test ./...

# Build a binary
go build -o myapp

x := 42  // Declared but never used
// main.go:5:2: x declared and not used (compile error!)

Practice Exercises