JavaScript Best Practices for HTML Integration

1. Use External Script Files

Recommended: Yes ✅

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

2. Where to Place Scripts

Option A: At the bottom of <body> (works, older style):

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

Option B (Better): Use defer in the <head>

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

3. Avoid async Unless Needed

Use only for independent scripts like analytics.

4. Inline Scripts

Use sparingly: okay for very small tasks.

<script>
  alert('Hello');
</script>

5. Minify Scripts in Production

Use tools like Terser, Webpack, or Vite for smaller file sizes and faster load.

6. Use Modern Syntax

Use let, const, arrow functions, etc. if you're not supporting old browsers.

7. Use Module Scripts (Optional)

<script type="module" src="main.js"></script>

Supports import/export and automatically defers execution.

Summary Table

Practice Recommendation
External scripts ✅ Yes
defer in <head> ✅ Yes
Inline scripts ❌ Avoid unless very small
async ⚠️ Only for independent scripts
Minify in production ✅ Yes
Modern syntax/modules ✅ Yes