JavaScript: Adding Scripts to HTML

Subject: javascript

⚙️ JavaScript: Adding Scripts to HTML

JavaScript is a powerful scripting language used to make web pages interactive and dynamic. It allows developers to manipulate the DOM, validate forms, add animations, handle events, and much more.

🔌 How to Include JavaScript in HTML

There are three common methods to embed JavaScript in a web page:

1. Inline JavaScript

  • Added directly within an HTML element using attributes like onclick, onmouseover, etc.

2. Internal JavaScript

  • Written inside a <script> tag within the HTML file.
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3. External JavaScript

  • Placed in a separate .js file and linked using the src attribute.
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🧠 Where to Place <script> Tags

📍 1. Inside <head> (with defer or async)

  • Loads before HTML rendering starts.
  • Can block rendering unless defer or async is used.
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📍 2. At the End of <body> (Recommended)

  • Executes after the HTML is fully loaded.
  • Improves load speed and avoids render-blocking.
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🧪 Example: Interactive JavaScript in HTML

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✅ Key Points

  • Use the <script> tag to include JavaScript.
  • Inline event handlers like onclick offer quick interaction.
  • Place scripts at the bottom of <body> to enhance performance.
  • Use defer or async if placing scripts in the <head>.
  • Keep large scripts in external .js files for cleaner code and easier maintenance.

🧠 Key Takeaway

JavaScript brings interactivity to static HTML pages. For best performance and user experience:

  • Place scripts just before the closing </body> tag.
  • Use internal <script> tags for small snippets.
  • Use external files for modular and maintainable code.