Thread: Calculator help.

Hello Skinnyskinny,

Welcome to the Java Programming Forums.

Have you started coding any of this yet?

OK well seeing as this is an assignment, i'm not happy about doing all of this for you. You need to learn!!

I have put together the basic program for you here. You will need to figure out how to add the info to the arrays & do the calculations etc..

import java.util.Scanner;
import java.util.ArrayList;
 
public class ShoppingCalculator {
 
    /**
     * JavaProgrammingForums.com
     */
    static String description, yesOrNo;
    static double cost;
    static int numberOfItems, quantity;
 
    public static ArrayList<String> array = new ArrayList<String>();
 
    // Setup Scanner class for reading user input
    public static Scanner scanner = new Scanner(System.in);
    public static Scanner scanner2 = new Scanner(System.in);
 
    public static void Calculate() {
 
        System.out.println("Please Enter Number of Items You Bought: ");
        numberOfItems = scanner.nextInt();
 
        for(int a = 0; a < numberOfItems; a++){            
 
                System.out.println("Please Enter Details For Item " + (a+1));
                System.out.println("===================================");
 
                System.out.println("Items Description Is: ");
                description = scanner2.nextLine();                
 
                System.out.println("Cost Per Item Is: ");
                cost = scanner2.nextDouble();
 
                System.out.println("Please Enter Quantity Bought: ");
                quantity = scanner2.nextInt();
 
                System.out.println("Please Confirm (y/n): ");
                yesOrNo = scanner2.next();
 
                if(yesOrNo.equals("y")){
                    System.out.println("You entered YES");
                    // Array code here
                }
                if(yesOrNo.equals("n")){
                    System.out.println("You entered NO");
                    // Possibly call Calculate method again
                }
 
                System.out.println("");
        }
 
    }
 
    public static void Total() {
 
        // Code to workout totals here
        System.out.println("Total");
    }
 
    public static void main(String[] args) {
 
        ShoppingCalculator sc = new ShoppingCalculator();
 
        System.out.println("*****Shopping Expenditure Calculator****");
        System.out.println("1.Calculate Shopping Expenditure");
        System.out.println("2.Display Total Expenditure");
        System.out.println("3.Exit");
        System.out.println("");
        System.out.println("Please Enter Your Choice: ");
 
        while (scanner.hasNext()) {
 
            int selection = scanner.nextInt();
 
            if (selection == 1) {
                sc.Calculate();
            } else if (selection == 2) {
                sc.Total();
            } else if (selection == 3) {
                scanner.close();
                System.out.println("Thank you for using Shopping Expenditure Calculator. Bye!");
                System.exit(0);
            }
        }
    }
 
}

I sent you a message, but i'm going to post the pseudo code here again:
shopcal class:

import java.util.*;
import java.text.*;
 
 
public class shopcal
{
    public static void main (String[] args) throws Exception
    {
        Item[] items = new Item[100];
        DecimalFormat fmt = new DecimalFormat("0.00");
        int numItems = 0;
        while (true)
        {
            // Get the top-level menu choice
            String choice = getMenuChoice();
            if (choice.equals("1"))
            {
                // Calculate shopping calculator choice
                // get item description
                String description = getItemDescription(numItems);
                // get total item price
                double price = getItemPrice();
                // get the quantity of that item
                int number = getItemQuantity();
                // Set only if confirmation is recieved
                if (getConfirmation())
                {
                    // create a new item and add it
                    items[numItems] = new Item(description, price, number);
                    // TODO: increase the number of items
                }
 
            }
            else if (choice.equals("2"))
            {
                // display total expenditure choice
                System.out.println("Display Item's Individual Cost & Total Cost");
                System.out.println("=============================================");
                for (int i = 0; i < numItems; i++)
                {
                    // TODO: what should be printed out for each item?
                    // use items[i].(attribute goes here) to access the item's attributes
                    // ex: items[i].description gets the item's description
                }
            }
            else if (choice.equals("3"))
            {
                // quit choice
                return;
            }
            else
            {
                // invalid menu choice
                // TODO: print out an error message if choice was not 1, 2, or 3
            }
        }
    }
 
    public static String getMenuChoice ()
    {
        Scanner input = new Scanner(System.in);
        System.out.println("****Shopping EXpenditure Calculator****");
        System.out.println("1. Calculate Shopping Calculator");
        System.out.println("2. Display Total Expenditure");
        System.out.println("3. Exit");
        System.out.println("***************************************");
        System.out.print("Please Enter Your Choice: ");
        return input.nextLine();
    }
 
    public static String getItemDescription (int itemNum)
    {
        // here's a completed example of how getting each attribute should look like
        Scanner input = new Scanner(System.in);
        System.out.println("Please ener detials for item " + itemNum);
        System.out.println("==================================");
        System.out.print("Item 1's Description is : ");
        return input.nextLine();
    }
 
    public static double getItemPrice ()
    {
        // TODO: finish this method
        Scanner input = new Scanner(System.in);
        double price = 0;
        // TODO: print out what you want to ask the user
        // TODO: read in from scanner
        // TODO: return the price (as double)
        return price;
    }
 
    public static int getItemQuantity ()
    {
        // TODO: finish this method
        Scanner input = new Scanner(System.in);
        int quantity = 0;
        // TODO: print out what you want to ask the user
        // TODO: read in from scanner
        // TODO: return the quantity (as int)
        return quantity;
    }
 
    public static boolean getConfirmation ()
    {
        // TODO: finish this method
        Scanner input = new Scanner(System.in);
        String read = "";
        // TODO: print out what you want to ask the user
        // TODO: read in from scanner
        // TODO: check to see if y/n, return appropriate true (y) or false (n)
        if (read.equals("y"))
        {
            return false;
        }
        else if (read.equals("n"))
        {
            return false;
        }
        else
        {
            // TODO: handle invalid input
            // throw an exception
            throw new RuntimeException();
        }
    }
}

Item class:

public class Item
{
    public String description;
    public int    numItems;
    public double unitCost;
 
    public Item (String description, double unitCost, int numItems)
    {
        this.description = description;
        this.unitCost = unitCost;
        this.numItems = numItems;
    }
}