What potential pitfalls should be considered when organizing PHP files for database functions, form validation, and result output in a larger application?

Potential pitfalls when organizing PHP files for database functions, form validation, and result output in a larger application include code duplication, lack of separation of concerns, and difficulty in maintaining and scaling the application. To address these issues, it's important to follow a modular approach by organizing related functionalities into separate files or classes, using proper naming conventions, and implementing design patterns like MVC (Model-View-Controller) for better organization and maintainability.

// Example of organizing database functions, form validation, and result output in separate files

// database.php
class Database {
    public function connect() {
        // Database connection logic
    }

    public function query($sql) {
        // Database query logic
    }
}

// validation.php
class Validation {
    public function validateForm($formData) {
        // Form validation logic
    }
}

// result.php
class Result {
    public function outputResult($resultData) {
        // Result output logic
    }
}