How can PHP developers ensure that form submissions work consistently across different browsers?

PHP developers can ensure that form submissions work consistently across different browsers by using server-side validation in addition to client-side validation. This means validating the form data on the server to ensure its accuracy and security, regardless of how the form was submitted. By doing this, developers can prevent any potential issues that may arise from variations in browser behavior.

// Server-side validation example
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $name = $_POST["name"];
    $email = $_POST["email"];
    
    // Validate form data
    if (empty($name) || empty($email)) {
        echo "Please fill out all required fields.";
    } else {
        // Process form submission
        // Insert data into database, send email, etc.
    }
}