Abstract in Java?

Java Abstract Class

• An abstract class in Java is a class declared with the abstract keyword.
• It is used to achieve abstraction, which means hiding implementation details and showing only essential functionality.

Key Features of Abstract Class

• Cannot create objects directly
• Can contain abstract methods and normal methods
• Must be inherited by another class
• Used as a base class

Syntax

abstract class ClassName {

}

Main Method

Car c = new Car();

Creates object for child class, not abstract class.

Important point

Vehicle v = new Vehicle();

Because abstract class objects cannot be created.

Abstract Method in Java

• An abstract method is a method declared without a body.
• It contains only the method declaration, and the implementation is provided by the subclass.

Syntax

abstract void sound();

• No method body
• Ends with semicolon ;

Important points:

• Abstract methods can only be inside an abstract class
• Child class must implement the abstract method
• Used to achieve abstraction.

Rule

If a class contains an abstract method, the class must be abstract.

abstract class Animal {

    abstract void sound();
}