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")

Note: Every multi-line comment that starts with /* must be closed with */, otherwise the compiler treats everything after it as a comment.

Challenge

Beginner

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

Add // at the start of the line that prints Goodbye!
The line printing Goodbye! should become a comment so it does NOT run
Do not delete any line, and do not change the line that prints Hello, Go!

Try it yourself

package main

import "fmt"

func main() {
    // Type your code below
    // Turn the line below into a comment so it stops running
    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.

All lessons in Fundamentals

2Variables and Basic Data Types

What is a variable Type Inference with `:=`Integers (int)Floating-Point Numbers Booleans Strings Zero Values Constants Naming Conventions Recap - Variables and Types

5Basic Input/Output

Formatted Output Format Verbs Printing Types Getting Basic User Input Recap - Input and Output

8Functions

Understanding Functions Declaring a Function Calling Functions Function Parameters Returning a Single Value Returning Multiple Values Named Return Values Function Scope Basics Recap - Creating Reusable Code

11Composite Types: Slices

Introduction to Slices Declaring Slice Literals Creating Slices with `make`Slice Length vs Capacity Accessing Slice Elements Appending Elements Slicing Existing Slices/Arrays Iterating Over Slices Copying Slices Recap - Dynamic Lists

14Basic Error Handling

The Concept of Errors The `error` Interface Functions Returning Errors Checking for Errors Creating Simple Errors Creating Formatted Errors Basic Error Handling Recap - Handling Problems

Practice on your own: Online Go compiler