# Input Validation
 
Input validation checks that user-supplied data conforms to expected formats and constraints before processing it. PHP's `filter_var()` function supports filters for emails, URLs, integers, floats, and IP addresses. Custom validation logic handles domain-specific rules like password strength or username format.

Visit the following resources to learn more:

- [@official@Input Validation](https://www.php.net/manual/en/book.filter.php)