Programming Example
Define a class ElectricBill with the following specifications:
Study this program carefully to understand the logic, output, and explanation in a structured way.
Define a class ElectricBill with the following specifications:
class : ElectricBill
Instance variables / data member:
String n — to store the name of the customer
int units — to store the number of units consumed
double bill — to store the amount to be paid
Member methods:
void accept( ) — to accept the name of the customer and number of units consumed
void calculate( ) — to calculate the bill as per the following tariff:
| Number of units | Rate per unit |
|---|---|
| First 100 units | Rs.2.00 |
| Next 200 units | Rs.3.00 |
| Above 300 units | Rs.5.00 |
A surcharge of 2.5% charged if the number of units consumed is above 300 units.
void print( ) — To print the details as follows:
Name of the customer: ………………………
Number of units consumed: ………………………
Bill amount: ………………………
Write a main method to create an object of the class and call the above member methods.
import java.util.Scanner;
public class ElectricBill
{
private String n;
private int units;
private double bill;
public void accept() {
Scanner in = new Scanner(System.in);
System.out.print("Enter customer name: ");
n = in.nextLine();
System.out.print("Enter units consumed: ");
units = in.nextInt();
}
public void calculate() {
if (units <= 100)
bill = units * 2;
else if (units <= 300)
bill = 200 + (units - 100) * 3;
else {
double amt = 200 + 600 + (units - 300) * 5;
double surcharge = (amt * 2.5) / 100.0;
bill = amt + surcharge;
}
}
public void print() {
System.out.println("Name of the customer\t\t: " + n);
System.out.println("Number of units consumed\t: " + units);
System.out.println("Bill amount\t\t\t: " + bill);
}
public static void main(String args[]) {
ElectricBill obj = new ElectricBill();
obj.accept();
obj.calculate();
obj.print();
}
}Enter customer name: Rumman Ansari
Enter units consumed: 123
Name of the customer : Rumman Ansari
Number of units consumed : 123
Bill amount : 269.0
Press any key to continue . . .
First read the algorithm, then study the program code line by line. After that, compare the code with the output and finally go through the explanation. This approach helps learners understand both the logic and the implementation properly.
After understanding this example, try to rewrite the same program without looking at the code. Then change some values or logic and run it again. This helps improve confidence and keeps learners engaged on the page for longer.