HTML Comment Tag: Creating Annotations in HTML

The comment tag is used to insert comments within HTML source code. For more details on the HTML comment tag, refer to the article below from Mytour.

Exploring the HTML Comment Tag

1. HTML Comment Tag

To add comments, annotations into HTML source code, we utilize the following syntax:

Important Note:

- Using three dots indicates a comment, an annotation that we include.

- In the syntax above, there's a lone hash mark at the beginning of the tag, but the closing tag is absent.

- Browsers don't display annotations or comments, yet they help record HTML source code.

By employing the comment tag, we can add messages and reminders in HTML.

Example 1: Below is an example illustrating the usage of the comment tag in HTML:

The output result after using the

comment tag appears as follows:

Additionally, the comment tag aids in HTML debugging. This is because we can add comments for each line of HTML code to troubleshoot errors.

Example 2: The following example demonstrates how to use the comment tag for HTML debugging:

The output result after applying the comment tag for HTML debugging appears as follows:

2. Valid and Invalid Comments in HTML

In HTML, comments cannot be nested, meaning one comment cannot be placed inside another. The second hyphen '--' may not display within a comment except it's part of the closing tag -->. Additionally, ensure no spaces within the opening comment tag.

Example 1: Below is an example of a valid comment that browsers will ignore:

The output result appears as follows:

Example 2: The following example illustrates an invalid comment that browsers display. This comment is invalid because it contains a space between the angle brackets and the hyphen.

The output result appears as follows:

3. Multi-line Comments in HTML

In addition to single-line comments, HTML also supports multi-line comments.

We can create a multi-line comment by placing the tag on the last line, as shown in the example below.

Example: Below is an example of multi-line comments in HTML:

The output result after applying multi-line comments appears as follows:

4. Conditional Comments in HTML

Conditional comments in HTML only work on Internet Explorer (IE) browser on Windows, on IE v5.0 and older versions. Other web browsers ignore this type of comment. We can use conditional comments to provide conditional instructions for different versions of IE.

Example: Below is an example illustrating the usage of conditional comments in HTML:

The output result appears as follows:

5. Using Comment Tags in HTML

Some browsers support the comment tag to add comments, annotations in HTML code.

Note: HTML5 no longer supports the comment tag.

Example: Below is an example of using the comment tag in HTML:

If not using the IE browser, the output result appears as follows:

In this article, Mytour just introduced you to the comment tag in HTML. Additionally, if you have any questions or need clarification, readers can leave their comments below the article.

In the next article, Mytour will further introduce you to the color property, color in HTML.