Why Don’t Self-Closing Script Elements Work?

If you think that <script /> should work as a valid self-closing tag, then you are wrong. If you use it in your code, it can produce unexpected output. In this blog, you will get the reason why the self-closing <script /> element doesn’t work inside code.

Table of Contents:

• Understanding Self-Closing Tags in HTML
• The Nature of <script> Elements
• How Browsers Parse <script />
• Differences Between HTML and XHTML
• Practical Consequences of Using <script />
• Best Practices for Writing <script> Elements
• Conclusion

Understanding Self-Closing Tags in HTML

HTML is used to create the structure of the website. HTML follows a syntax where some elements can be self-closing..

Examples of such elements include:

<img />, <br />, <input />, <meta /> and <hr />

These elements do not contain any content. However, <script> does not fall into this category because it is used to write JavaScript code inside an HTML document.

The Nature of <script> Elements

The <script> element is not a self-closing element. It is a container element, which means it contains JavaScript code that lies under the opening and closing script tags. If you don’t want to write the JavaScript code inside the script tag, then you can use the src attribute. Here is how you can do it:

For example, valid script elements include:

<script>

console.log("Hello, World!");

</script>

and

<script src="script.js"></script>

Attempting to write <script /> causes issues because browsers do not interpret it as a closed element, leading to unexpected behaviour of your website.

Top Web Development Courses to Kickstart Your Coding Journey

Professional Web Development Courses

Explore Program

How Browsers Parse <script />

If you give HTML documents to web browsers, then web browsers parse HTML documents using the HTML specification rules. So, when a web browser encounters a self-closing script tag (<script />), it does not recognize it as a self-closing tag but instead considers it an open <script> tag without a closing tag. As a result:

• The browser continues parsing everything until it finds a valid closing </script> tag.
• If the closing tag is missing, the browser may misinterpret the rest of the document as script content, breaking the page layout.

Differences Between HTML and XHTML

Previously, XHTML (Extensible Hypertext Markup Language) was used, which allows self-closing tags for all elements, including the <script /> element. However, HTML5, which is used now, does not follow XHTML’s rules and treats <script /> differently. Browsers parsing  HTML5 documents don’t recognize self-closing <script /> correctly and produce an unexpected output.

Practical Consequences of Using <script />

Using a self-closing <script /> tag can produce several issues. Here are some of the common issues:

• The document object model (DOM) structure is disrupted.
• Code that follows the <script /> tag may be considered as part of the script block.
• An incorrect HTML structure can affect search engine indexing and accessibility tools.
• Different browsers may handle the incorrect syntax in varying ways, leading to unexpected behavior.

Best Practices for Writing <script> Elements

Here are some best practices that everyone needs to follow while writing <script> elements:

1. Always Use Closing Tags:

<script>

  console.log(“Properly closed script tag.”);

</script>

2. For External Scripts, Use the src Attribute:

<script src=”script.js”></script>

3. Use HTML Validator Tools

Run your code through an HTML validator to catch syntax errors early.

4. Avoid Using XHTML Syntax in HTML5

If writing XHTML, ensure your document is served with the correct MIME type (application/xhtml+xml).

Conclusion

Self-closing <script> elements do not work because the <script> tag is not a void element and requires an explicit closing tag to maintain proper document structure. Misusing self-closing script tags can lead to parsing errors, broken layouts, and unexpected behavior. By understanding HTML parsing rules and adhering to best practices, developers can write robust and error-free scripts, ensuring their web pages function as intended.

Why don’t self-closing script elements work? – FAQs