What is the purpose of interfaces in PHP and why is it important to adhere to their requirements?

Interfaces in PHP define a contract that classes must adhere to by implementing specific methods. By using interfaces, you can enforce a consistent structure across different classes, making your code more organized and maintainable. It is important to adhere to the requirements of interfaces to ensure that your classes are compatible with each other and can be easily swapped out without causing errors.

// Define an interface with required methods
interface LoggerInterface {
    public function log($message);
}

// Implement the interface in a class
class FileLogger implements LoggerInterface {
    public function log($message) {
        // Log message to a file
    }
}

// Implement another class that adheres to the interface
class DatabaseLogger implements LoggerInterface {
    public function log($message) {
        // Log message to a database
    }
}