Working with Variables

In this lesson you will learn the basic way to use variables in Go and understand its concise, type-inferred declarations. This is for anyone searching for "Go variables how to use" or "Go := how to use".

A variable is like a labelled box that stores a value under a name. := declares a variable without writing its type (type inference). fmt.Printf gives you formatted output.

The sample code declares name := "Alice" and age := 14 with :=, then assembles a message with format verbs in fmt.Printf("Hello, %s! You are %d years old\n", name, age). %s is the verb for a string and %d for an integer.

A common stumbling block for beginners is the strictness that comes with a statically typed language where types are fixed at compile time. It catches mistakes before you run, but a type mismatch is an immediate compile error. Go also has its own visibility rule worth noting: starting a name with a capital letter makes it "exported" and visible from other packages.

In real-world development this type inference lets you skip verbose type declarations while keeping the safety of compile-time type checking, which is why Go is trusted even in large systems.

📖 Reference code

package main

import "fmt"

func main() {
    name := "Alice"
    age := 14
    fmt.Printf("Hello, %s! You are %d years old\n", name, age)
}

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run Go directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).