using System;

public class Program

{

    public static void Main()

    {

                    // TESTING INVOICE CLASS

        // IN THIS MAIN CLASS I WILL TEST THE PERSON CLASS IN 3 DIFFERENT WAYS

        // EVERYTIME I TRY A NEW WAY I CREATE A NEW OBJECT

​

​

            // WAY 1 (with default arguments)

            Invoice invoice1 = new Invoice();

            invoice1.GetInvoiceAmount();

​

            // WAY 2 (by giving values to the arguemnts)

            Invoice invoice2 = new Invoice("5847", "This string can be anything", 5 , 10);

            invoice2.GetInvoiceAmount();

​

            // WAY 3 ()

            Invoice invoice3 = new Invoice();

​

            Console.Write("Part Number : ");

            invoice3.PartNumber = Console.ReadLine();

​

            Console.Write("Description : ");

            invoice3.Description = Console.ReadLine();

​

            Console.Write("Quantity : ");

            invoice3.Quantity = Convert.ToInt32(Console.ReadLine());

​

            Console.Write("Price Per Item : ");

            invoice3.PricePerItem = Convert.ToDecimal(Console.ReadLine());

​

            invoice3.GetInvoiceAmount();

​

​

            Console.ReadLine();

    }

        class Invoice

    {

        private string partNumber;

        private string description;

        private int quantity;

        private decimal pricePerItem;

​

        public string PartNumber

        {

            get

            {

                return partNumber;

            }

            set

            {

                partNumber = value;

            }

        }

​

        public string Description

        {

            get

            {

                return description;

            }

            set

            {

                description = value;

            }

        }

​

        public int Quantity

        {

            get

            {

                return quantity;

            }

            set

            {

                if (value > 0)

                    quantity = value;

            }

        }

​

        public decimal PricePerItem

        {

            get

            {

                return pricePerItem;

            }

            set

            {

                if (value > 0)

                    pricePerItem = value;

            }

        }

​

​

        public Invoice(string pN = "", string desc = "", int qtt = 0, decimal ppi = 0)

        {

            partNumber = pN;

            description = desc;

            quantity = qtt;

            pricePerItem = ppi;

        }

​

        public void GetInvoiceAmount()

        {

            decimal invoiceAmount = Quantity * PricePerItem;

​

            Console.WriteLine("Part Number : {0}", PartNumber);

            Console.WriteLine("Description : {0}", Description);

            Console.WriteLine("Quantity : {0}", Quantity);

            Console.WriteLine("Price Per Item : {0}", PricePerItem);

            Console.WriteLine("****** Invoice Amount : {0}", invoiceAmount);

​

            Console.WriteLine();

        }

​

​

    }

}