What Tag in JavaScript Contains Either Scripting Statements or External Js File?

In JavaScript, the <script> tag is used to contain either scripting statements or reference an external JavaScript file. This tag plays a crucial role in including JavaScript code within an HTML document.

Let’s explore the different ways in which we can use the <script> tag.

Inline JavaScript

Inline JavaScript refers to placing JavaScript code directly within an HTML document. To achieve this, we use the <script> tag with the code enclosed between opening and closing script tags.

<script>
    // Inline JavaScript code goes here
</script>

External JavaScript File

An alternative approach is to store the JavaScript code in a separate file and link it to your HTML document using the <script> tag. This method allows for better organization of code and reusability across multiple web pages.

<script src="path/to/your/script.js"></script>

Fallback Content

In case a browser does not support or has disabled JavaScript, you can provide fallback content by placing it between the opening and closing <noscript> tags within the <script> tags. This content will be displayed when JavaScript is not available.

<script>
    document.write("This message appears when Javascript is disabled.");
</script>
<noscript>
    <p&rt;JavaScript is disabled in your browser.&rt;</p&rt;
</noscript&rt;

Placement of the <script>

The <script> tag can be placed anywhere within the HTML document. However, it is common practice to include it within the <head> or <body> section of the document.

When placing it in the <head> section:

If the script contains code that modifies the HTML structure (e.g., adding or modifying elements), it is essential to ensure that the elements being manipulated are loaded before executing the JavaScript code. In such cases, using event listeners like window.onload or DOMContentLoaded is recommended.
If the script does not depend on any HTML elements, placing it in the head section allows for faster execution since it can start running as soon as possible.

When placing it in the <body> section:

If your JavaScript code relies on specific HTML elements that appear later in the document, placing the script at the end of the body ensures that those elements are already loaded and accessible when executing your code.
This placement may result in a slower initial page load since JavaScript execution will begin after all HTML content has been parsed and rendered.

To summarize, using the <script> tag with either inline JavaScript or an external JavaScript file allows us to include dynamic functionality within our HTML documents. By strategically placing these tags and considering fallback content, we can optimize how our scripts interact with our web pages and enhance user experiences.