Inheritance in Java

INHERITANCE

The word inheritance refers to the act

of inheriting material or immaterial possessions by succession .

materialimmaterial

Inheritance in java

• Inheritance is a basic concept in Object Oriented Programming .• Inheritance in java is a mechanism in which one class of objects acquires all the properties and behaviors of a parent class.• represents the IS-A / HAS-A relationship .

terms

•Superclass/base class/parent class : The class from which another class is derived .

•Subclass/derived class/child class : class that is derived from another class .

syntaxInheritance can be implemented

using the keyword extend .

class subclass_name extends superclass_name  {     //methods and fields  }  

superclass : employeesubclass : programmerrelation : IS A

programmer IS A employee .

example

source codeclass employee{  float salary=40000;  }  

class programmer extends Employee{   int bonus=10000;   public static void main(String args[]) {    programmer p=new programmer();    system.out.println(“programmer salary is :"+p.salary);    system.out.println(“ponus of Programmer is:"+p.bonus);   }  }  

outputprogrammer salary is : 40000.0 bonus of programmer is : 10000

types1.Single

inheritance .2.Multiple

inheritance .3.Multilevel

inheritance .4.Hierarchical inheritance

.5.Hybrid inheritance

.

Single inheritance

A single class is inherited from a single baseclass

example

Multiple inheritanceA single class is

inherited from a more than one baseclasses.

Java does not support multiple inheritance .

That is why java is said to be simple .

Multilevel

inheritance

A derived class acts as baseclass for another class .

example

Hierarchical inheritance

More than one class is inherited from a single baseclass

example

hybrid inheritance

a combination of single and multiple

 inheritance

advantages•Code reusability – object of a derived class can also access the field of its base class .•Method overriding – we can define a same method in a derived class without altering the function in base class .