How To Write Comments in JavaScript

February 8, 2024
How To Write Comments in JavaScript
Table of Contents
  • The Importance of Comments in Your Code
  • Single-line Comments
  • Multi-line Comments
  • How to Tag Comment in JavaScript
  • The Two Types of Comments in JavaScript
  • Conclusion

Welcome to our tutorial on effectively utilizing comments in JavaScript! Whether you're a beginner or an experienced developer, understanding how to properly comment your code is crucial for both collaboration and maintaining your work. Before we dive deep, let's take a quick look at what a comment might look like in JavaScript:

1// This is a single-line comment in JavaScript

By the end of this guide, you'll be adept at using comments to annotate your JavaScript code, making it more readable and maintainable.

The Importance of Comments in Your Code

Comments are a significant part of programming that can often be overlooked by newcomers. They allow you to leave notes and explanations within your code without affecting its execution. This is essential for several reasons:

  • Clarification: Explaining complex code logic for anyone who might review your code, including your future self.
  • Collaboration: Providing context for other developers in team projects, improving communication.
  • Debugging: Temporarily disabling code to isolate issues during troubleshooting.

Now, let's explore the different types of comments you'll encounter and use in JavaScript.

Single-line Comments

Single-line comments, as the name suggests, span only one line. They're perfect for brief notes or comments beside a line of code. Here's how you write them:

1// This is a single-line comment
2var example = "This is code"; // This comment follows code on the same line

To answer the question, "How do you comment text in JavaScript?"—you simply precede the text with two forward slashes (//). Anything following // on that line won't be executed by JavaScript.

Multi-line Comments

Sometimes you need more space to explain your code. This is where multi-line, or block comments, come into play. Here's the syntax:

1/* This is a multi-line comment
2which spans multiple lines. */

These comments can be used to annotate sections of your code or to temporarily disable blocks of code during debugging.

How to Tag Comment in JavaScript

Tagging comments doesn't have a specific syntax, but it often involves a consistent prefix that helps categorize comments. For example:

1// TODO: Refactor this function to improve performance

In this case, TODO acts as a tag that some development tools and IDEs recognize, making it easier to track tasks within the code.

The Two Types of Comments in JavaScript

To address "What are the two types of comments in JavaScript?"—we've already discussed them above. They are:

  1. Single-line comments: Initiated with //.
  2. Multi-line comments: Enclosed between /* and */.

Both serve the purpose of making your code understandable, but their application depends on the length and purpose of the comment you're writing.


Mastering the use of comments in JavaScript is a fundamental skill for any web developer. If you're looking to expand your knowledge even further, consider exploring our JavaScript course, or if you're just starting out, our Introduction to Web Development course covers the basics of HTML, CSS, and JavaScript.

For more resources on HTML and CSS, our HTML Fundamentals Course and Introduction to CSS can provide you with a solid foundation for web development.

Remember, writing clear comments is as important as writing clear code. They are your guideposts and annotations that make collaborative work possible and keep your codebase maintainable.

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