Java Abstract Class and Methods

Sun Microsystems created the high-level programming language Java. It was initially intended for interactive television, but it was quickly changed for the Internet. The syntax of Java, an object-oriented language, is quite similar to that of C++, however Java is more straightforward and capable than C++. Java uses abstract classes and methods, which is one of its key characteristics.

By specifying a set of behaviours that all objects in a class can share, abstract classes and methods offer a mechanism to organise large programmes. The behaviour of an object is defined by abstract classes, and the behaviour is implemented through methods. What abstract classes and methods are, how to use them, and how they work are all covered in this article.

public abstract class Animal {
  public abstract void move();
  public abstract void eat();
  public abstract void reproduce();
}

The abstract class declares three abstract methods, move(), eat(), and reproduce(), that

What Are Abstract Classes and Methods?

A class that cannot be instantiated but serves as a model or blueprint for other classes is known as an abstract class. An abstract class describes an object's structure but does not offer a way to execute the behaviour. It is a broad definition of an object that may be applied by other classes.

All objects in a class can have similar behaviours that are defined using abstract methods. Methods defined in an abstract class are known as abstract methods. They offer a means for kid classes to put their behaviour into practise without having to define it themselves.

Abstract Methods

Any class that extends the abstract class must implement abstract methods, which are methods without a body. They don't have a body and are declared in Java using the abstract keyword. They finish with a semicolon instead (;).

Any class that extends an abstract class must adhere to the contract established by the abstract methods. This contract guarantees that regardless of the implementation, every class that extends the abstract class will have the same fundamental functionality.

Why Are Abstract Classes and Methods Used?

Complex programmes employ abstract classes and methods for their structure. They offer a means of broadly describing an object and subsequently a means for child classes to implement their behaviour without individually specifying it. Complex software applications are now simpler to build because to this.

Additionally, abstract classes and methods offer a means of defining behaviour that is shared by other classes. For instance, an abstract class may specify how a shopping cart behaves, and then its subclasses might implement various shipping or payment options. This makes it simpler to develop flexible, expandable programmes.

AbstractClass.java

abstract class Shape {
   public abstract void draw();
}
class Circle extends Shape {
   @Override
   public void draw() {
      System.out.println("Drawing a circle");
   }
}
 class Rectangle extends Shape {
   @Override
   public void draw() {
      System.out.println("Drawing a rectangle");
   }
}
public class AbstractClass{
   public static void main(String[] args) {
      Shape circle = new Circle();
      Shape rectangle = new Rectangle();
      circle.draw(); // Output: Drawing a circle
      rectangle.draw(); // Output: Drawing a rectangle
   }
}

Output:

Drawing a circle
Drawing a rectangle

How Are Abstract Classes and Methods Used?

Java uses abstract classes and methods to describe behaviour that several classes may share. Although an abstract class specifies an object, it does not offer a behaviour's implementation. Child classes can implement their behaviour without having to define it by using the abstract methods specified in the abstract class.

In order to design programmes that are adaptable and extendable, abstract classes and methods are employed. They offer a means of broadly describing an object and, subsequently a means for child classes to implement their behaviour without individually specifying it. This makes it simpler to develop flexible, expandable programmes.

When Should Abstract Classes and Methods Be Used?

Complex applications should be created using abstract classes and methods. They offer a means of broadly describing an object and subsequently a means for child classes to implement their behaviour without individually specifying it. This makes it simpler to develop flexible, expandable programmes.

In order for child classes to implement an object's behaviour without having to specify it themselves, abstract classes and methods offer a mechanism to define an object's behaviour in a broad fashion. When developing applications that will be utilised by several developers, abstract classes and methods should also be employed. Because of this, it is simpler for several developers to work on the same application without having to reuse code or produce several versions of it.

Conclusion

The use of abstract classes and methods is crucial in Java programming. They offer a means of broadly describing an object and, subsequently, a means for child classes to implement their behaviour without individually specifying it. This makes it simpler to develop flexible, extendable sophisticated applications.

Abstract classes and methods should be used when writing large applications that several developers will utilise. They offer a means of broadly defining an object's behaviour before giving child classes a means of implementing it without having to specify it themselves. This enables different developers to work on the same application more easily without having to reuse code or produce numerous versions of it.

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