Java Overriding

Java overriding

Created By: chatGPT

In Java, method overriding allows a subclass to provide a specific implementation of a method that is already defined in its superclass. This is a crucial aspect of polymorphism in object-oriented programming. When a method in a subclass has the same name, return type, and parameters as a method in the superclass, the subclass method overrides the superclass method.

class Animal {
    void sound() {
        System.out.println("Animal makes a sound");
    }
}

class Dog extends Animal {
    @Override
    void sound() {
        System.out.println("Dog barks");
    }
}

public class Test {
    public static void main(String[] args) {
        Animal myDog = new Dog();
        myDog.sound();  // Outputs: Dog barks
    }
}

Important: When overriding a method, it's crucial to use the @Override annotation, which helps to ensure you are actually overriding a method from the superclass. If you mistakenly change the method signature, the compiler will generate an error if @Override is used, helping you avoid bugs.

class Cat extends Animal {
    @Override
    void sound() {
        System.out.println("Cat meows"); // Correctly overrides animal sound method
    }
}

public class Example {
    public static void main(String[] args) {
        Animal myCat = new Cat();
        myCat.sound(); // Outputs: Cat meows
    }
}

A method in a subclass can only override a method in a superclass if:

The method in the superclass is not declared as final, static, or private.
The overridden method must have the same return type or a subtype (covariant return type) in the subclass. The ability to override methods is a key feature of Java that promotes runtime polymorphism.

class Bird extends Animal {
    @Override
    void sound() {
        System.out.println("Bird chirps");
    }
}

public class Demo {
    public static void main(String[] args) {
        Animal myBird = new Bird();
        myBird.sound(); // Outputs: Bird chirps
    }
}