Go Comments

Part of the Fundamentals section of Coddy's GO journey — lesson 4 of 109.

Comments are notes you write inside your code. The compiler completely ignores them - they exist only to help humans understand the code.

To write a single-line comment, use //. Everything after // until the end of the line is ignored:

// This is a comment
fmt.Println("Hello, World!")

A comment can also be written at the end of a line, after the code:

fmt.Println("Hello, World!") // This prints Hello, World!

For comments that span several lines, use /* to start and */ to end:

/* This is a multi-line comment.
   The compiler ignores all of it. */
fmt.Println("Welcome!")

Comments can also temporarily disable a line of code without deleting it:

// fmt.Println("This line will NOT run")
fmt.Println("This line will run")

Challenge

Beginner

Fix the code so that only Hello, Go! is printed.

Cheat sheet

Comments in Go:

Single-line comment:

// This is a comment
fmt.Println("Hello!") // Comment after code

Multi-line comment:

/* This is a
   multi-line comment */

Disabling code:

// fmt.Println("This will NOT run")
fmt.Println("This will run")

Try it yourself

package main

import "fmt"

func main() {
    // Type your code below
    ? fmt.Println("Goodbye!")
    fmt.Println("Hello, Go!")
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

2Variables and Basic Data Types

5Basic Input/Output

8Functions

11Composite Types: Slices

14Basic Error Handling