Why Abstract Class is used in Java?

A class is an abstract class if it contains at least one abstract method. It can contain other non-abstract methods as well. A class can be declared as abstract by using the abstract keyword. Also, an abstract class cannot be instantiated.

A program that demonstrates an abstract class in Java is given as follows:

Example

 Live Demo

abstract class Animal {
   abstract void sound();
}
class Cat extends Animal {
   void sound() {
      System.out.println("Cat Meows");
   }
}
class Dog extends Animal {
   void sound() {
      System.out.println("Dog Barks");
   }
}
class Cow extends Animal {
   void sound() {
      System.out.println("Cow Moos");
   }
}
public class Demo {
   public static void main(String[] args) {
      Animal a;
      a = new Cat();
      a.sound();
      a = new Dog();
      a.sound();
      a = new Cow();
      a.sound();
   }
}

Output

Cat Meows
Dog Barks
Cow Moos

Rishi Raj

Published on 15-Feb-2019 10:17:24

• Related Questions & Answers
• Why Final Class used in Java?
• Abstract class in Java
• Why can't a Java class be both abstract and final?
• Differences between abstract class and concrete class in Java
• Can we define an abstract class without abstract method in java?
• What is the difference between abstract class and a concrete class in Java?
• Can we define an abstract class with no abstract methods in Java?
• Difference between Abstract Class and Interface in Java
• Differences between abstract class and interface in Java
• Explain abstract class in PHP.
• Why GeckoDriver is used in selenium?
• Why can't static method be abstract in Java?
• Why String class is immutable or final in Java?
• Why Object class is the super class for all classes in Java?
• Can a class in Java be both final and abstract?