What are the best practices for handling user input and form data in PHP to prevent security vulnerabilities?

To prevent security vulnerabilities when handling user input and form data in PHP, it is important to sanitize and validate the data before using it in your application. This can help prevent SQL injection, cross-site scripting (XSS), and other common security threats. One way to achieve this is by using PHP's filter_var() function to sanitize and validate input data. 

// Example of sanitizing and validating user input using filter_var()

// Retrieve user input from a form field
$userInput = $_POST['user_input'];

// Sanitize and validate the user input
$sanitizedInput = filter_var($userInput, FILTER_SANITIZE_STRING);

// Use the sanitized input in your application
echo "Sanitized input: " . $sanitizedInput;

Keywords

SQL injection Cross-site scripting (XSS) Data validation htmlspecialchars Prepared statements

Related Questions