What are the advantages of handling form validation and processing on the server side in PHP?

Handling form validation and processing on the server side in PHP ensures that the data submitted by users is validated and sanitized before being processed, reducing the risk of security vulnerabilities such as SQL injection or cross-site scripting attacks. This approach also allows for more control over the data being submitted, enabling the server to enforce specific validation rules and ensure data integrity.

// Validate and process form data on the server side
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // Validate form data
    $name = htmlspecialchars($_POST["name"]);
    $email = filter_var($_POST["email"], FILTER_VALIDATE_EMAIL);
    
    // Process form data
    if ($name && $email) {
        // Data is valid, proceed with processing
        // For example, save the data to a database
    } else {
        // Data is invalid, handle errors accordingly
    }
}