Page 400 - CITS - Computer Software Application -TT

COMPUTER SOFTWARE APPLICATION - CITS

Code Reusability
Using an abstract class in the code saves time. We can call the abstract method wherever the method is necessary.
Abstract class avoids the process of writing the same code again.
Abstraction
Data abstraction in Java helps the developers hide the code complications from the end-user by reducing the
project’s complete characteristics to only the necessary components.
Dynamic Resolution
Using the support of dynamic method resolution, developers can solve multiple problems with the help of one
abstract method.

Before moving forward, let’s first understand how to declare an abstract class.

Java Interfaces and their advantages

An interface in Java is a blueprint of a class. It has static constants and abstract methods.

The interface in Java is a mechanism to achieve abstraction. There can be only abstract methods in the Java
interface, not method body. It is used to achieve abstraction and multiple inheritance in Java.
In other words, you can say that interfaces can have abstract methods and variables. It cannot have a method
body.
Java Interface also represents the IS-A relationship
It cannot be instantiated just like the abstract class.
Since Java 8, we can have default and static methods in an interface.

Since Java 9, we can have private methods in an interface.

Method Overriding in Java

If subclass (child class) has the same method as declared in the parent class, it is known as method overriding
in Java.
In other words, If a subclass provides the specific implementation of the method that has been declared by one
of its parent class, it is known as method overriding.
Usage of Java Method Overriding
• Method overriding is used to provide the specific implementation of a method which is already provided by its
superclass.
• Method overriding is used for runtime polymorphism
Rules for Java Method Overriding
1 The method must have the same name as in the parent class

2 The method must have the same parameter as in the parent class.
3 There must be an IS-A relationship (inheritance).

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CITS : IT&ITES - Computer Software Application - Lesson 109 - 115 CITS : IT&ITES - Computer Software Application - Lesson 109 - 115