Question

Create a class named Invoicing that includes three overloaded computeInvoice() methods for a book store: see pages 196 for examples… The 8% tax should be defined as a constant.
1. When computeInvoice() receives a single parameter, it represents the price of one book ordered. Add 8% tax and display the total due.
2. When computeInvoice() receives two parameters, they represent the price of a book and the quantity ordered. Multiply the two values, add 8% tax, and display the total due.
3. When computeInvoice() receives three parameters, they represent the price of a book, the quantity ordered, and a coupon value. Multiply the quantity and price, reduce the result by the coupon value, and then add 8% tax and display the total due.
Create a driver class named TestInvoice with a main() method that tests all three overloaded methods using the following data: Price $24.95 Price, $17.50, quantity 4, Price $10.00, quantity 6, coupon $20.00 Output printed to Eclipse Console:
Price $26.95
Price $76.95
Price $43.20

Answer 1

Answer:

Follows are the method to this question:

class Invoicing  //defining a class Invoicing  

{

  public static final double Tax = 8.0; //defining static variable Tax that holds a value

  public static double Total;//defining a double variable Total

  public void computeInvoice(double p1)//defining method computeInvoice that take double parameter

  {

      Total = p1 + p1 * (Tax / 100);//defining double variable Total that holds Price value

      System.out.printf("Price $%.2f\n" , Total);//print calculated value

  }

  public void computeInvoice(double p2, int q)//defining method computeInvoice that takes integer and double parameter

  {

      Total = p2 * q;//use Total variable that calculate Price with Tax

      Total = Total + (Total * (Tax/ 100));//calculate taxes on Total

      System.out.printf("Price $%.2f\n" , Total);//print calculated value

  }  

  public void computeInvoice(double p3, int q, double c)//defining method computeInvoice that takes one integer and two-double parameter  

  {

      Total = p3 * q;//use Total to calculate Total price

      Total = Total - c;//remove coupon amount from Total amount

      Total = Total + (Total * (Tax/ 100));//calculate taxes on Total

      System.out.printf("Price $%.2f\n" , Total);//print calculated value

  }

}

public class TestInvoice  //defining Main class TestInvoice  

{

  public static void main(String[] ar)//defining main method  

  {

      Invoicing  obm = new Invoicing ();//creating Invoicing class object obm

      obm.computeInvoice(24.95);//calling method computeInvoice

      obm.computeInvoice(17.5, 4);//calling method computeInvoice

      obm.computeInvoice(10, 6, 20);//calling method computeInvoice

  }

}

Output:

please find attached file.

Explanation:

In the above-given code, a class "Invoicing" is defined, inside the class two static double variable "Total and Tax" is defined, in which the Tax variable holds a value that is "8.0".

In class three same method, "computeInvoice" is used that accepts a different parameter for providing method overloading, which can be defined as follows:

• In the first method, it accepts a single double parameter "p1", and inside the method, it uses the "Total" variable to calculate price value.
• In the second method, it accepts one integer and one double parameter "q and p2", and inside the method, it uses the "Total" variable is used to calculate the price with tax and print its value.
• In the third method, it accepts one integer and two double parameters "q, p3, and c", and inside the method, it uses the "Total" variable is used to calculate the price with tax and include tax and print its value.
• In the next step, the main class "TestInvoice" is defined inside the main method, Invoicing object is created and call its method.