The @Override annotation

The `@Override` annotation is used in Java to indicate that a method in a subclass is overriding a method with the same signature in its superclass. It is not mandatory to use `@Override`, but it helps in detecting errors during compilation if the method signature does not match any method in the superclass.

Here are some key points about `@Override`:

1. Purpose: It provides compile-time checking that a method is indeed overriding a method from a superclass. If there is a mismatch in the method signature (e.g., misspelling of method name, incorrect parameters), the compiler will generate an error.

2. Usage: `@Override` is placed immediately before the method declaration in the subclass that is intended to override a method in the superclass.

3. Compatibility: `@Override` annotation was introduced in Java 5. It can only be used with methods that are overriding a superclass method. If a method is not overriding a superclass method, using `@Override` will result in a compilation error.

4. Benefits: Helps in code maintenance and readability by clearly indicating that a method is intended to override a method from the superclass. It also ensures that the method signature is correct.

Here's an example demonstrating the usage of `@Override`:

class Animal {

    void makeSound() {

        System.out.println("Animal makes a sound");

    }

}

class Dog extends Animal {

    @Override

    void makeSound() { // Overriding the makeSound method from the superclass

        System.out.println("Dog barks");

    }

}

public class Main {

    public static void main(String[] args) {

        Animal animal = new Dog(); // Creating an instance of Dog but referenced as Animal

        animal.makeSound(); // Calls the makeSound method of Dog class

    }

}

In this example, the `makeSound()` method in the `Dog` class overrides the `makeSound()` method in the `Animal` class. The `@Override` annotation is used to explicitly indicate that the method is intended to override a method from the superclass. If there is a mistake in the method signature, such as misspelling `makeSound` as `makeSounds`, the compiler will generate an error, helping to catch errors early in the development process.