Question

Give an object that could be represented through super and sub classes? Give an example and describe what you think would be data member in the super class and then what would be data member in the subclass. Please create a UML diagram for one of the classes described. You can do this by inserting a table or list in the post or create it in Cacoo.

Answer 1

Here I have provided the answer for above question:

import java.lang.*;
import java.util.*;

//Parent (or) Super class
class Person
{
   String name,address;
   long phone_number;
   String email_address;
  
   public Person(String name,String address,long phone_number,String email_address)
   {
       this.name=name;
       this.address=address;
       this.phone_number=phone_number;
       this.email_address=email_address;
   }
  
   @Override
   public String toString()
   {
       System.out.println("This is Person class");
      
       return ("Name:"+name+"\n"+"Address:"+address+"\n"+"PhoneNo:"+phone_number+"\n"+"Email:"+email_address+"\n");
   }
}

//Child (or) Sub class
class Employee extends Person
{
   String office;
   double salary;
   String date_hired;
  
   public Employee(String name,String address,long phone_number,String email_address,String office,double salary,String date_hired)
   {
       super(name,address,phone_number,email_address);   //this will call the super class constructor.
       this.office=office;
       this.salary=salary;
       this.date_hired=date_hired;
   }
  
   @Override
   public String toString()
   {
       System.out.println("This is Employee class");
      
       return (super.toString()+"Office:"+office+"\n"+"salary:"+salary+"\n"+"Date Hired:"+date_hired+"\n");

       // here super.toString() calls the method in super class,super key word is used to call super class membes
   }

}

//Child (or) Sub class
class Student extends Person
{
   String status;
  
   public Student(String name,String address,long phone_number,String email_address,String status)
   {
       super(name,address,phone_number,email_address);   //this will call the super class constructor.
       this.status=status;
   }
  
   @Override
   public String toString()
   {
       System.out.println("This is Student class");
      
       return (super.toString()+"Status of student:"+status+"\n");

       // here super.toString() calls the method in super class,super key word is used to call super class membes
      
   }

}

//For Testing-----this class is used create object of sub classes and
public class Test
{
   public static void main(String args[])
   {
      
       Employee e=new Employee("sofia","Kirlampudi",234234,"mail address","ADP",50000,"21-12-2018"); //creating the object of sub class employee.
       System.out.println(e.toString());
      
       Student st=new Student("sofia","Kirlampudi",234234,"mail address","Senior");      //creating the object of subclass Student.
       System.out.println(st.toString());
      
   }
}

In the above code i have explained the relationship between super class and sub class, and how to call super class method using sub class object.

so,here the data members of super class are:

                                                                                   1.name, 2.address, 3.phone_number, 4.email_address

the data members of sub class Employee are:

                                                                                1.Office 2.salary,3. date_hired.

the data members of sub class Student are:

                                                                                1.Status

UML Diagram:

Visibility of Data:

- private

+public

#protected

~default

Diagram:

Person -name :String -address: String -phone numberlong -email address:String +toString0 Student Employee -status: String -office:String -salary: double -date_hired:String +toString0 +toString0

Hoping that the above answer will help you...Thank you...