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🐳 Go — Learn From Zero

Playground: Go Playground — click, type, run.

What is Go?

Go (Golang) is a fast, statically-typed language by Google. Built for concurrency and cloud infrastructure.

  • Cloud services & microservices
  • DevOps tooling (Docker, Kubernetes)
  • High-performance APIs
  • CLI tools

Run Online — No Install

Use the playground links above.

🟢 Beginner — Core Basics

Your First Program

go
package main
import "fmt"
func main() {
  fmt.Println("Hello, world!")
}

Every program has package main.

Variables & Types

go
var age int = 36
height := 1.78
name := "Ada"
isStudent := true

Use := for short declaration.

If / Else

go
if age := 18; age >= 18 {
  fmt.Println("Vote")
} else {
  fmt.Println("Too young")
}

If can include an init statement.

Loops

go
for i := 0; i < 5; i++ {
  fmt.Println(i)
}

Go has only for loops.

Functions

go
func add(a int, b int) int {
  return a + b
}

Types come after names.

Slices & Maps

go
fruits := []string{"apple", "banana"}
fruits = append(fruits, "cherry")
m := map[string]int{"Ada": 36}

Slices are dynamic; maps are built-in.

🟡 Intermediate — Building Real Programs

Structs

go
type Person struct {
  Name string
  Age  int
}
p := Person{"Ada", 36}

Group fields in structs.

Methods

go
func (p Person) Greet() string {
  return "Hi " + p.Name
}

Methods have a receiver.

Interfaces

go
type Stringer interface { String() string }
// satisfied implicitly

Duck typing via interfaces.

Error Handling

go
f, err := os.Open("a.txt")
if err != nil {
  log.Fatal(err)
}

Errors are values, checked explicitly.

Packages

go
import (
  "fmt"
  "os"
)

Group imports in parentheses.

🔴 Advanced — Pro Concepts

Goroutines

go
go func() {
  fmt.Println("async")
}()

Lightweight threads via go.

Channels

go
ch := make(chan int)
go func() { ch <- 1 }()
fmt.Println(<-ch)

Communicate via channels.

Sync & Mutex

go
var mu sync.Mutex
mu.Lock()
// critical section
mu.Unlock()

Protect shared state.

Generics (Go 1.18+)

go
func Map[T any](s []T, f func(T) T) []T { return s }

Type parameters with any.

What's Next?

  • Build a tiny project: Calculator, To-Do App, Weather Widget
  • Read the official docs and a good book
  • Solve Exercism exercises
  • Join a community & share your code

Practice daily for 20 minutes. Consistency > intensity.