Lesson 19 of 20

PHP Best Practices

Security Best Practices

Security is critical for PHP web applications. Follow these practices to protect against common vulnerabilities.

  • Always use prepared statements for database queries (prevent SQL injection)
  • Escape output with htmlspecialchars() (prevent XSS)
  • Validate and sanitize all user input
  • Use password_hash() and password_verify() for passwords
  • Use CSRF tokens in forms
  • Keep PHP and dependencies updated
  • Set secure cookie flags (httponly, secure, samesite)

Code Quality

Write clean, maintainable PHP code by following modern standards.

  • Follow PSR coding standards (PSR-1, PSR-12)
  • Use type declarations for parameters and return types
  • Use Composer for dependency management
  • Use namespaces to organize code
  • Prefer constructor promotion (PHP 8)
  • Use named arguments for clarity (PHP 8)
  • Write unit tests with PHPUnit