Best Practices in JavaScript

Writing good JavaScript is about more than making it work – it's about making it readable, maintainable, and efficient. These practices help you avoid bugs and make collaboration easier.

Use Strict Mode

Add "use strict"; at the top to catch common mistakes.

Naming Conventions

• Variables/functions: camelCase (myVariable)
• Constants: UPPER_SNAKE_CASE (API_KEY)
• Classes: PascalCase (MyClass)
• Private properties: _prefix or # for real private (ES2022)

Prefer const and let over var

Avoid var – it has function scope and hoisting issues.

Write Clear and Readable Code

• Use meaningful names
• Keep functions small and focused
• Add comments for complex logic
• Consistent formatting (use Prettier/ESLint)

Error Handling

Always handle possible errors, especially in async code.

Performance Tips

• Avoid unnecessary DOM queries – cache selections
• Use event delegation for dynamic elements
• Debounce/throttle expensive event handlers
• Prefer for...of over forEach for simple loops

Security Basics

• Never trust user input
• Use textContent over innerHTML when possible
• Validate/sanitize data
• Use HTTPS

Quick Quiz