Introduction

Go (also called Golang) is a fast, compiled, open-source programming language created at Google, designed to be simple to read and to handle many tasks at once with built-in concurrency.

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Part of the free Go course at LearnCodingFast — hands-on lessons with examples you run in your browser, plus practice exercises and a quick quiz.

By the end of this lesson you'll understand what makes Go special, you'll know what every line of a Go program does, and you'll have written and run your own first program that prints to the screen.

What You'll Learn in This Lesson

1️⃣ What is Go?

Go (also called Golang) was created at Google in 2009 to fix everyday frustrations: slow compile times, messy dependencies, and how hard it was to write programs that do many things at once. It stands on four ideas you'll feel in every project:

That combination is why Go powers Docker, Kubernetes, and a huge slice of modern cloud infrastructure. In this lesson you'll start where every Go programmer starts: a tiny program that prints text. Read the worked example below first — every line is explained — then run it yourself.

2️⃣ The Four Parts of Every Go Program

Look back at that example. Every Go program you ever write has the same four building blocks, in this order:

This next example shows the small but important differences between Println (adds a newline and spaces) and Print (adds neither). Read the comments, predict the output, then check.

Your turn. The program below works once you fill in the two blanks marked ___ . Follow the 👉 hints, then run it and compare with the expected output.

3️⃣ Running Your Code with go run

To run a Go file on your own machine, you save it (for example as main.go ) and use the go run command in your terminal. It compiles and runs the program in one step — perfect while you're learning and experimenting.

One more guided exercise to lock in the structure. Three pieces of the skeleton are missing — fill each ___ using the hints.

No blanks this time — just a brief and an outline to keep you on track. Write it yourself, run it, and check your output against the example in the comments. This is exactly the kind of tiny program that builds real fluency.

📋 Quick Reference — Go Basics

Practice quiz

Which package name marks a Go program you can run directly?

  • package run
  • package main
  • package app
  • package start

Answer: package main. package main is special: it marks a runnable program. Other names produce importable libraries.

Which function does Go call first when a program starts?

  • func start()
  • func init()
  • func run()
  • func main()

Answer: func main(). func main() is the entry point; Go calls it first in a package main program.

Which standard package provides Println for printing text?

  • io
  • fmt
  • os
  • log

Answer: fmt. fmt (say 'fumpt') is the standard library's formatting and printing package.

What does fmt.Println do after writing its values?

  • Nothing extra
  • Adds a newline
  • Adds a tab
  • Clears the screen

Answer: Adds a newline. Println means 'print line': it writes the values, then moves to a new line.

What separator does fmt.Println put between multiple values?

  • A comma
  • A tab
  • A space
  • Nothing

Answer: A space. Println inserts a single space between multiple arguments.

How do fmt.Print calls behave compared to Println?

  • They add no trailing newline
  • They add two newlines
  • They add a tab
  • They print backwards

Answer: They add no trailing newline. Print adds no automatic newline or spaces, so output continues on the same line.

What happens in Go if you import a package but never use it?

  • A warning only
  • Nothing
  • A compile error
  • It runs slower

Answer: A compile error. An unused import is a compile error in Go, which keeps code clean.

Which command compiles and runs a Go file in one step?

  • go compile main.go
  • go run main.go
  • go exec main.go
  • go start main.go

Answer: go run main.go. go run main.go compiles and runs the program in a single command.

Where must the opening brace of func main go?

  • On the next line
  • On the same line as func main()
  • Anywhere
  • It is optional

Answer: On the same line as func main(). Go requires the opening brace on the same line: func main() {, not on a new line.

Why must exported names like Println start with a capital letter?

  • For speed
  • It is just style
  • The capital makes them public
  • To save memory

Answer: The capital makes them public. A leading capital letter is what makes a name exported (callable from outside the package).