Day 3: Java Notes

 Day 3: Java Notes



Day: 3,4,5 And 6


Inheritance:

 We can access one class properties  into another class using extends keyword and reusable code purpose.

  • Memory wastage is low.

  • To reduce Object memory we go for inheritance.



Heap memory:

Object we stored in heap memory

RAM->JVM-> Heap memory.


Type of inheritance:

  • Single inheritance

  • Multilevel inheritance

  • Multiple inheritance

  • Hybrid inheritance

  • Hierarchical inheritance


Types of  inheritance:

======================


Single inheritance:

----------------------

Combinations of one parent class and one child class.


Multilevel inheritance:

--------------------------

Child class is accessing more than one parent class in a tree level structure

 

Hierarchical inheritance

-------------------------------

Combination of  one parent and more than one child


Multiple inheritance:

--------------------------

Child class is accessing more than one parent class parallelly.

Java doesn’t support multiple inheritance.

  • Priority problem.

  • Syntax error/ compilation error


Hybrid Inheritance

---------------------------

Combination of Multiple and Hierarchical inheritance




Java does not support Multiple Inheritance:


- Syntax

- Priority Problem


 



Assignment:

 

QUESTION 1:

-----------

     Project   :COmputer

     Class     :Computer

     Methods   :computerModel()


     Class     :Desktop

     Methods   :desktopSize()


Description:

create above 2 class and call all your class methods into the Desktop using single inheritance.



QUESTION 2:

------------

     Project   :EducationInformation

     Package   :org.edu

     Class     :Education

     Methods   :ug(),pg()


     Class     :Arts

     Methods   :bsc(),bEd(),bA(),bBA()


     Class     :Engineering

     Methods   :bE(),bTech()


     Class     :Medicine

     Methods   :physiyo(),dental(),mbbs()


Description:

create above 4 class and call all your class methods into the Education using multilevel inheritance.

QUESTION 3:

------------

     package name: org.india

     Project name: SouthIndia

     Class name  : India

     Methods     : india



     Class name  : TamiladuN

     Methods     : tamillanguage

  

  


     Class name  : kerala

     Methods     : malayalam


    

     Class name  : AndhraPradesh

     Methods     : telugu


Description:

create above 4 class and call india methods into all the sub class using Hierarchical inheritance.




single inheritance:

package org.employee;


public class Client {

public void clientName() {

System.out.println("swiggy");

}


}


package org.employee;


public class Company extends Client {

public void companyName() {

System.out.println("HCL");

}

public void companyID() {

System.out.println("hc293l");

}


}


-------------------------------------------------------------------------------------------


multilevel inheritance:


package org.employee;


public class Client {

public void clientName() {

System.out.println("swiggy");

}


}


package org.employee;


public class Company extends Client {

public void companyName() {

System.out.println("HCL");

}

public void companyID() {

System.out.println("hc293l");

}


}


package org.employee;


public class Emp extends Company {

public void empName() {

System.out.println("jeba");

}

public void empID() {

System.out.println("h1002");

}

public static void main(String[] args) {

Emp s= new Emp();

s.empName();

s.empID();

s.companyName();

s.companyID();

s.clientName();

}

}

------------------------------------------------------------------------------------------------------------------------

Hierarchical inheritance:

package org.bank;


public class RBI {

public void rule() {

System.out.println("rules");

}


}


package org.bank;


public class HDFC extends RBI{

public void feature() {

System.out.println("loan");

System.out.println("saving");

System.out.println("fixed");

}

public static void main(String[] args) {

HDFC h= new HDFC();

h.feature();

h.rule();

}

}


package org.bank;


public class SBI extends RBI {

public void feature() {

System.out.println("loan");

System.out.println("saving");

System.out.println("fixed");

}

public static void main(String[] args) {

SBI s= new SBI();

s.feature();

s.rule();

}


}

----------------------------------------------------------------------------------------------------------------------


Multiple inheritance :

Program:


package org.multi;


public interface RBIBank {

void saving();

void fixed();


}

—-------------------------------------------------------

package org.multi;


public interface WorldBank {

void loan();

void deposit();


}


—---------------------------------

package org.multi;


public class HDFC implements RBIBank, WorldBank {

@Override

public void saving() {

// TODO Auto-generated method stub

System.out.println("saving");

}

@Override

public void deposit() {

// TODO Auto-generated method stub

System.out.println("deposit");

}

@Override

public void fixed() {

// TODO Auto-generated method stub

System.out.println("fixed");

}

@Override

public void loan() {

// TODO Auto-generated method stub

System.out.println("loan");

}

public static void main(String[] args) {

 HDFC h= new HDFC();

 h.saving();

 h.loan();

 

}

}


—-----------------------------------------------------------------------------------------------------------------------



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