Solution to Revision Test 2

import javax.swing.JOptionPane;

public class HandPhone2 {
    public static int getModel() {
        String input;
        int modelNo;

        do {
            input = JOptionPane.showInputDialog(null,
                                                "Enter Model No.: \n" +
                                                "1 - Nokia N10 \n" +
                                                "2 - Nokia S20 \n" +
                                                "3 - Nokia K30 \n" +
                                                "4 - Nokia E40 \n" +
                                                "5 - Nokia D50 \n",
                                                "Handphone",
                                                JOptionPane.QUESTION_MESSAGE);

            modelNo = Integer.parseInt(input);
            if (modelNo < 1 || modelNo > 5) {
                JOptionPane.showMessageDialog(null, "Model No. must be 1 to 5",
                                              "Error",
                                              JOptionPane.ERROR_MESSAGE);
            }

        } while (modelNo < 1 || modelNo > 5);

        return modelNo;
    }

    public static int getQuantity() {
        String input;
        int qty;
        do {
            input = JOptionPane.showInputDialog(null,
                                                "Enter no. of handphones to purchase");
            qty = Integer.parseInt(input);

            if (qty <= 0) {
                JOptionPane.showMessageDialog(null,
                                              "Quantity must be more than 0",
                                              "Error",
                                              JOptionPane.ERROR_MESSAGE);
            }
        } while (qty <= 0);

        return qty;
    }

    public static void displayInfo(int modelNo, int qty) {
        String modelName = "";

        double price = 0, totPrice;

        switch (modelNo) {
        case 1:
            modelName = "Nokia N10";
            price = 1000;
            break;
        case 2:
            modelName = "Nokia S20";
            price = 888;
            break;
        case 3:
            modelName = "Nokia K30";
            price = 600;
            break;
        case 4:
            modelName = "Nokia E40";
            price = 400;
            break;
        case 5:
            modelName = "Nokia D50";
            price = 100;
            break;
        } //end switch

        totPrice = qty * price;

        JOptionPane.showMessageDialog(null, "Total purchase price for " +
                                      qty + " " + modelName + " is $" +
                                      totPrice);

    }

    public static void main(String[] args) {
        int modelNo, qty;

        modelNo = getModel();
        qty = getQuantity();

        displayInfo(modelNo, qty);

    }
}