DEV Community

loading...

How to create comments in an HTML file

jordanholtdev profile image Jordan Holt Originally published at blog.jordanholt.dev on ・3 min read

Comments are a great way to help keep your projects organized. If you’re working on a team or looking back at an older code base you’ll be glad to have used comments to help explain your process. In this post you’ll learn how to create comments in an HTML file.

Why use comments?

Here’s a few reasons why you might want to use comments in an HTML file.

  • Use comments to help your future self understand why you used specific HTML
  • Use comments to help team members explain changes or updates
  • Remove sections of HTML you don’t want displayed. This could be for testing purposes.
  • Leave specific comments in production to help clients or end-users understand the HTML layout. For example if you create themes for a specific framework.

Adding comments

An HTML comment begins with <!-- and ends with -->.To create an comment in HTML we wrap the comment in those special markers which the browser will then ignore and not display.

<!-- Everything inside these markers will be a comment and will be ignored by the browser -->

<h1>This is a heading and will be rendered by the browser</h1>

Here are a couple of examples of how you might use comments.

<!-- Added a simple form below for the mailing list. Needs input validation -->

<div class="form-container">
  <form action="" method="get" class="form-example">
    <div class="form-example">
      <label for="name">Enter your name: </label>
      <input type="text" name="name" id="name" required />
    </div>
    <div class="form-example">
      <label for="email">Enter your email: </label>
      <input type="email" name="email" id="email" required />
    </div>
    <div class="form-example">
      <input type="submit" value="Subscribe!" />
    </div>
  </form>
  <div />
</div>

Above we left a comment indicating changes to the HTML file, in this case the addition of a simple form.We also left a note that the form still requires input validation.

Let’s have a look at another example.

<!-- I updated the form and temporarily removed the Name input field for testing -->

<div class="form-container">
  <form action="" method="get" class="form-example">
    <!-- <div class="form-example">
      <label for="name">Enter your name: </label>
      <input type="text" name="name" id="name" required />
    </div> -->
    <div class="form-example">
      <label for="email">Enter your email: </label>
      <input type="email" name="email" id="email" required />
    </div>
    <div class="form-example">
      <input type="submit" value="Subscribe!" />
    </div>
  </form>
  <div />
</div>

In the example above we added a comment that refers to a change in the form. We also removed or commented out part of the form for testing purposes. The HTML will that is between the special markers <!-- --> will be ignored by the browser.

When to avoid using comments

Comments are a great way to keep organized, particularly when in development but here are a few scenerios when you should avoid using comments.

  1. You have a ton of of HTML that’s been commented out in your production code.
  • In this case you might want to remove the HTML that isn’t being used, as a larger HTML file can effect speed.
  1. Storing any private data in comments.
  • While the browser will ignore comments it is still possible to view the source code using dev tools
  1. The comments serve no purpose.
  • If your comments are not actually helping to explain changes or updates then lose them. The morelines of code the more chance of an error.

Wrap up

HTML comments are a great way to add notes in the code to explain changes or updates. This is really useful if you are returning to a project after a long time away or there are multiple people working on the same code base. We create an HTML comment by wrapping it with these special markers <!---->.

Make sure to check out the HTML5 Specs for a bit more information on HTML comments.

Discussion

pic
Editor guide