Chapter 9, Problem 4PE

Explanation of Solution

Program:

File name: “Salesperson.java”

//Define a class named Salesperson

public class Salesperson

{

    //Declare the private variables

    private int id;

    private double sales;

    /*Define a method named Salesperson

    that takes two arguments*/

    Salesperson(int idNum, double amt)

    {

        //Assign the values

        id = idNum;

        sales = amt;

    }

    //Define a get method that returns the ID number

    public int getId()

    {

        //Return the value

        return id;

    }

    //Define a get method that returns the sales value

    public double getSales()

    {

        //Return the value

        return sales;

    }

    //Define a set method that takes the ID number

    public void setId(int idNum)

    {

        //Assign the value

        id = idNum;

    }

    //Define a set method that takes the sales value

    public void setSales(double amt)

    {

        //Assign the value

        sales = amt;

    }

}

File name: “SalespersonSort.java”

//Import necessary header files

import javax.swing.*;

//Define a class named SalespersonSort

public class SalespersonSort

{

    //Define a main method

    public static void main(String[] args)

    {

        //Declare an array to store seven Salesperson objects

        Salesperson[] salespeople = new Salesperson[7];

        //Declare the variables

        int x;

        int id;

        double sales;

        String order;

        String message = "";

        //For loop to be executed until x exceeds 7

        for(x = 0; x < salespeople.length; ++x)

        {

            //Prompt the user to enter an ID number

id = Integer.parseInt(JOptionPane.showInputDialog(null,

            "Enter an ID number"));

            //Prompt the user to enter the sales value

sales = Double.parseDouble(JOptionPane.showInputDialog(null,

            "Enter sales value"));

            salespeople[x] = new Salesperson(id, sales);

        }

        /*Prompt the user to enter the choice of displaying

the objects in order by either ID number or sales value*/

        order = JOptionPane.showInputDialog(null,

         "By which field do you want to sort?\n" +

         "(I)d number or (S)ales");

        //If the user enters the choice, ID number

        if(order.charAt(0) == 'I')

            //Function call

            sortById(salespeople);

        //Else the user enters the choice, sales value

        else

            //Function call

            sortBySales(salespeople);

        //For loop to be executed until x exceeds 7

        for(x = 0; x < salespeople...