What are common errors when using $_POST in PHP forms?

When using $_POST in PHP forms, common errors include:

• Form method mismatch: Ensure that the form method is set to post. If it’s set to get, $_POST will be empty.
• Missing enctype attribute: For file uploads, the form must have enctype="multipart/form-data". Without it, file data will not be sent.
• Uninitialized variables: Check if the form fields exist before accessing them with isset() or empty() to avoid undefined index notices.
• Data sanitization and validation: Always sanitize and validate user inputs to prevent security vulnerabilities like XSS and SQL injection.