Problem Statement: To demonstrate the concept of abstract class and method.

Algorithm

Step 1: Start
Step 2: create abstract class special with n static method
Step 3: double process(double p,double r)
Step 4: create class discount extends special
Step 5: create tax which extends special
Step 6: tax t=new tax()
Step 7: discount d=new discount()
Step 8: Read b,c
Step 9: a=d.process(b,c)
Step 10: Read b,c
Step 11: print the value of discount
Step 12: a=t.process(b,c)
Step 13: print the value of tax
Step 14: stop

Function process(double p,double r) of class discount

Step 1: Start
Step 2: net=(p-(p*(r/100)))
Step 3: return net
Step 4: exit

Function process(double p,double r) of class tax

Step 1: Start
Step 2: total=(p+(p*(r/100)))
Step 3: return total
Step 4: Exit.

Program

import java.io.*;

abstract class Special 
{
	abstract double Process(double p,double r);
}

class Discount extends Special
{
	double net;
	double Process(double p,double r) 
	{
		net=p-p*(r/100);
		return net;
	}
}

class Tax extends Special
{
	double total;
	double Process(double p,double r) 
	{
		total=p+p*(r/100);
		return total;
	}
}

public class MySubAbs {
	public static void main(String args[])
	{
		double ret,p,r;
		DataInputStream in=new DataInputStream(System.in);
		Discount d=new Discount();
		Tax t=new Tax();
		try
		{
			System.out.println("Enter P and R to compute discount : ");
			p=Double.parseDouble(in.readLine());
			r=Double.parseDouble(in.readLine());
			ret=d.Process(p,r);
			System.out.println("Discount : "+ret);
			System.out.println("Enter P and R to compute tax : ");
			p=Double.parseDouble(in.readLine());
			r=Double.parseDouble(in.readLine());
			ret=t.Process(p,r);
			System.out.println("Tax : "+ret);	
		}
		catch(Exception e)	
		{ 
			System.out.println("Error : " + e);
		}
	}
}

Output

Enter P and R to compute discount :
20
30
Discount : 14.0
Enter P and R to compute tax :
50
60
Tax : 80.0

Enter P and R to compute discount :
250
30
Discount : 175.0
Enter P and R to compute tax :
666
30
Tax : 865.8

Abstract class and methods in Java is a post from ShoutToWorld - Let's Learn Let's Shout - Helping bloggers and developers.