Method Overriding

Method Overriding

In Java, method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass. Here's a summarized breakdown:

1. Basic Method Overriding:

   • If the same method is present in both the superclass and the subclass, the method in the subclass overrides the one in the superclass.

   • The @Override annotation is used to inform the compiler about the intention to override, though it's not mandatory.

   // Example 1: Method Overriding
   class Animal {
      public void displayInfo() {
         System.out.println("I am an animal.");
      }
   }
   
   class Dog extends Animal {
      @Override
      public void displayInfo() {
         System.out.println("I am a dog.");
      }
   }
   
   class Main {
      public static void main(String[] args) {
         Dog d1 = new Dog();
         d1.displayInfo(); // Output: I am a dog.
      }
   }

2. Using super Keyword:

   • The super keyword is used in the subclass to call the overridden method of the superclass.

   // Example 2: Use of super Keyword
   class Animal {
      public void displayInfo() {
         System.out.println("I am an animal.");
      }
   }
   
   class Dog extends Animal {
      public void displayInfo() {
         super.displayInfo();
         System.out.println("I am a dog.");
      }
   }
   
   class Main {
      public static void main(String[] args) {
         Dog d1 = new Dog();
         d1.displayInfo();
         // Output:
         // I am an animal.
         // I am a dog.
      }
   }

3. Access Specifiers in Method Overriding:

   • The access specifier in the subclass should provide larger access than the access specifier in the superclass.

   // Example 3: Access Specifier in Overriding
   class Animal {
      protected void displayInfo() {
         System.out.println("I am an animal.");
      }
   }
   
   class Dog extends Animal {
      public void displayInfo() {
         System.out.println("I am a dog.");
      }
   }
   
   class Main {
      public static void main(String[] args) {
         Dog d1 = new Dog();
         d1.displayInfo(); // Output: I am a dog.
      }
   }

4. Overriding Abstract Methods:

   In Java, abstract classes are created to be the superclass of other classes. And, if a class contains an abstract method, it is mandatory to override it.

Method overriding is crucial for achieving polymorphism in Java and providing specific behaviors in subclasses while maintaining a consistent interface in the superclass.