What are the best practices for handling user input validation in PHP to ensure data integrity?

User input validation is crucial in PHP to ensure data integrity and prevent security vulnerabilities such as SQL injection or cross-site scripting attacks. Best practices for handling user input validation include sanitizing input data, validating input against expected formats, and using prepared statements for database queries. 

// Example of handling user input validation in PHP
$userInput = $_POST['user_input'];

// Sanitize input data
$cleanInput = filter_var($userInput, FILTER_SANITIZE_STRING);

// Validate input against expected format
if (preg_match('/^[a-zA-Z0-9]+$/', $cleanInput)) {
    // Input is valid, proceed with processing
    // Use prepared statements for database queries to prevent SQL injection
    $stmt = $pdo->prepare("INSERT INTO table (column) VALUES (:input)");
    $stmt->bindParam(':input', $cleanInput);
    $stmt->execute();
} else {
    // Input is not valid, handle error
    echo "Invalid input. Please enter alphanumeric characters only.";
}

Keywords

filter_var htmlentities validation data integrity security

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