(Package Inheritance Hierarchy)

Question

Package-delivery services such as FedEx® DHL® and UPS® offer a number of different shipping options each with specific costs associated. Create an inheritance hierarchy to represent various types of packages. Use Package as the base class of the hierarchy then include classes TwoDayPackage and OvernightPackage that derive from Package. Base class Package should include private instance variables representing the name address city state and ZIP code for the package's sender and recipient and instance variables that store the weight (in ounces) and cost per ounce to ship the package. Package's constructor should initialize these private instance variables with public properties. Ensure that the weight and cost per ounce contain positive values. Package should provide a public method CalculateCost that returns a decimal indicating the cost associated with shipping the package. Package's CalculateCost method should determine the cost by multiplying the weight by the cost per ounce. Derived class TwoDayPackage should inherit the functionality of base class Package but also include an instance variable that represents a flat fee that the shipping company charges for two-day delivery service. TwoDayPackage's constructor should receive a value to initialize this instance variable. TwoDayPackage should redefine method CalculateCost so that it computes the shipping cost by adding the flat fee to the weight-based cost calculated by base class Package's CalculateCost method. Class OvernightPackage should inherit directly from class Package and contain an instance variable representing an additional fee per ounce charged for overnight- delivery service. OvernightPackage should redefine method CalculateCost so that it adds the additional fee per ounce to the standard cost per ounce before calculating the shipping cost. Write a test application that creates objects of each type of Package and tests method CalculateCost.

Vulpes · Answer

Try this: using System; public class Package { string senderName; string senderAddress; string senderCity; string senderState; string senderZip; string recipientName; string recipientAddress; string recipientCity; string recipientState; string recipientZip; decimal weight; decimal costPerOunce; public string SenderName { get{ return senderName; } set{ senderName = value; } } public string SenderAddress { get{ return senderAddress; } set{ senderAddress = value; } } public string SenderCity { get{ return senderCity; } set{ senderCity = value; } } public string SenderState { get{ return senderState; } set{ senderState = value; } } public string SenderZip { get{ return senderZip; } set{ senderZip = value; } } public string RecipientName { get{ return recipientName; } set{ recipientName = value; } } public string RecipientAddress { get{ return recipientAddress; } set{ recipientAddress = value; } } public string RecipientCity { get{ return recipientCity; } set{ recipientCity = value; } } public string RecipientState { get{ return recipientState; } set{ recipientState = value; } } public string RecipientZip { get{ return recipientZip; } set{ recipientZip = value; } } public decimal Weight { get{ return weight; } set { if (value > 0) weight = value; else Console.WriteLine(Weight can't be less than zero); } } public decimal CostPerOunce { get{ return costPerOunce; } set { if (value > 0) costPerOunce = value; else Console.WriteLine(Cost per ounce can't be less than zero); } } public Package ( string senderName string senderAddress string senderCity string senderState string senderZip string recipientName string recipientAddress string recipientCity string recipientState string recipientZip decimal weight decimal costPerOunce ) { SenderName = senderName; SenderAddress = senderAddress; SenderCity = senderCity; SenderState = senderState; SenderZip = senderZip; RecipientName = recipientName; RecipientAddress = recipientAddress; RecipientCity = recipientCity; RecipientState = recipientState; RecipientZip = recipientZip; Weight = weight; CostPerOunce = costPerOunce; } public virtual decimal CalculateCost() { return weight * costPerOunce; } } public class TwoDayPackage : Package { decimal twoDayDeliveryFee; public decimal TwoDayDeliveryFee { get { return twoDayDeliveryFee; } set { twoDayDeliveryFee = value; } } public TwoDayPackage ( string senderName string senderAddress string senderCity string senderState string senderZip string recipientName string recipientAddress string recipientCity string recipientState string recipientZip decimal weight decimal costPerOunce decimal twoDayDeliveryFee ) : base ( senderName senderAddress senderCity senderState senderZip recipientName recipientAddress recipientCity recipientState recipientZip weight costPerOunce ) { TwoDayDeliveryFee = twoDayDeliveryFee; } public override decimal CalculateCost() { return base.CalculateCost() + TwoDayDeliveryFee; } } public class OvernightPackage : Package { decimal overnightDeliveryFeePerOunce; public decimal OvernightDeliveryFeePerOunce { get { return overnightDeliveryFeePerOunce; } set { overnightDeliveryFeePerOunce = value; } } public OvernightPackage ( string senderName string senderAddress string senderCity string senderState string senderZip string recipientName string recipientAddress string recipientCity string recipientState string recipientZip decimal weight decimal costPerOunce decimal overnightDeliveryFeePerOunce ) : base ( senderName senderAddress senderCity senderState senderZip recipientName recipientAddress recipientCity recipientState recipientZip weight costPerOunce ) { OvernightDeliveryFeePerOunce = overnightDeliveryFeePerOunce; } public override decimal CalculateCost() { return (CostPerOunce + OvernightDeliveryFeePerOunce) * Weight; } } class Test { static void Main() { Package p = new Package ( John Smith 3256 Epiphenomenal Avenue Minneapolis Minnesota MN 55416 Fred Smith 220 Second Avenue St. Petersburg Florida FL 33705 160M 0.1M ); Console.WriteLine(p.CalculateCost()); TwoDayPackage tdp = new TwoDayPackage ( John Smith 3256 Epiphenomenal Avenue Minneapolis Minnesota MN 55416 Fred Smith 220 Second Avenue St. Petersburg Florida FL 33705 160M 0.1M 1.5M ); Console.WriteLine(tdp.CalculateCost()); OvernightPackage op = new OvernightPackage ( John Smith 3256 Epiphenomenal Avenue Minneapolis Minnesota MN 55416 Fred Smith 220 Second Avenue St. Petersburg Florida FL 33705 160M 0.1M 0.02M ); Console.WriteLine(op.CalculateCost()); Console.ReadKey(); } }