In Java, abstract means incomplete .

It is used when a class or method is not fully finished and child classes must complete it.

Abstract Class

A class declared with abstract keyword is called an abstract class.

abstract class Animal { }

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Cannot create object directly

Mostly used as parent class

Animal a = new Animal (); // ❌ Error

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Abstract Method

An abstract method has:

only declaration

no body

abstract void sound ();

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Child class must implement it.

Example

abstract class Animal { abstract void sound (); }

class Dog extends Animal { void sound () { System . out .…