Question

Case Problem 11 - 1:

Modify the GreenvilleRevenue program created in the previous chapter so that it performs the following tasks:

The program prompts the user for the number of contestants in this year’s competition; the number must be between 0 and 30. Use exception-handling techniques to ensure a valid value and display the error message: Number must be between 0 and 30

The program prompts the user for talent codes. Use exception-handling techniques to ensure a valid code and update the displayed message to the following message: x is not a valid talent code. Assigned as Invalid.

where x was the invalid code entered into the console.

After data entry is complete, the program prompts the user for codes so the user can view lists of appropriate contestants. Use exception-handling techniques for the code verification and display the following message: x is not a valid code

where x was the invalid code entered into the console

Answer 1

Answer:---                                                      Date:--29/03/2019

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GreenvilleRevenue
{
class Chapter10
{
static void Main()
{
int thisYearContestants;

Console.WriteLine("Please enter the number of contestants entered in this year's competition: ");
thisYearContestants = GetContestants();

Contestant[] contestants = new Contestant[thisYearContestants];

FillArrays(thisYearContestants, contestants);
  

double totalrevenue = 0;
foreach (Contestant c in contestants)
{
totalrevenue += c.EntryFee;
Console.WriteLine(c);
}
Console.WriteLine("\n ********************************************************** \n");
Console.WriteLine("\nTotal Revenue: $" + totalrevenue);

PromptTalentCodes(thisYearContestants, contestants);
}

static int GetContestants()
{
int contestants = -1;
string input = Console.ReadLine();
bool valid = false;
while (!valid)
{
try
{
if (!Int32.TryParse(input, out contestants) || (contestants < 0 || contestants > 30))
{
throw new Exception("Error. Please enter a value between 0 and 30.");
}
else
{
valid = true;
}
}
catch(Exception e)
{
Console.WriteLine(e.Message);
input = Console.ReadLine();
}
}
return contestants;
}

static void FillArrays(int thisYearContestants, Contestant[] contestants)
{
int x = 0;
string name;
int age;
char talent;
while (x < thisYearContestants)
{
Console.WriteLine("\nEnter Contestant Name: ");
name = Console.ReadLine();
Console.WriteLine("Enter Contestant age: ");
int.TryParse(Console.ReadLine(), out age);
Console.WriteLine("Talent codes are:");
for (int k = 0; k < Contestant.talentCodes.Length; ++k)
Console.WriteLine(" {0} {1}", Contestant.talentCodes[k], Contestant.talentStrings[k]);
Console.WriteLine("Please enter contestant " + (x + 1) + "'s talent code: ");

char.TryParse(Console.ReadLine(), out talent);
if (age <= 12)
{
contestants[x] = new ChildContestant();
contestants[x].Name = name;
contestants[x].TalentCode = talent;
++x;
}
else if (age > 12 && age <= 17)
{
contestants[x] = new TeenContestant();
contestants[x].Name = name;
contestants[x].TalentCode = talent;
++x;
}
else
{
contestants[x] = new AdultContestant();
contestants[x].Name = name;
contestants[x].TalentCode = talent;
++x;
}
}
}

static void PromptTalentCodes(int thisYearContestants, Contestant[] contestants)
{
int x;
char QUIT = 'Q';
char input;
bool isValid;
bool correct;

Console.WriteLine("\n ********************************************************** \n");

Console.WriteLine("To see the contestants by talent, please search a valid talent code or " + QUIT + " to quit: ");
Console.WriteLine("\nThe types of talent are:");
for (x = 0; x < Contestant.talentStrings.Length; ++x)
Console.WriteLine("{0, -6}{1, -20}", Contestant.talentCodes[x], Contestant.talentStrings[x]); //taken from ch9 sample problem

isValid = false;
while (!isValid)
{
if (!char.TryParse(Console.ReadLine(), out input))
{
isValid = false;
Console.WriteLine("\nInvalid talent code. Please enter a valid talent code or " + QUIT + " to quit: ");
}
else
{
if (input == QUIT)
isValid = true;
else
{
for (int k = 0; k < Contestant.talentCodes.Length; ++k)
{
if (input == Contestant.talentCodes[k])
{
isValid = true;
}
}
try
{
if (!isValid)
{
throw new Exception(input + " is not a valid code.\n Please enter a talent code or " + QUIT + " to quit: ");
}
else
{
Console.WriteLine("\nContestants with talent " + input + " are: ");
correct = false;
for (x = 0; x < thisYearContestants; ++x)
{
if (contestants[x].TalentCode == input)
{
Console.WriteLine(contestants[x].Name);
correct = true;
}
}
if (!correct)
Console.WriteLine("No contestants entered with talent " + input + ".");
isValid = false;
Console.Write("\nEnter another talent code or " + QUIT + " to quit: ");
}
}
catch(Exception e)
{
Console.WriteLine(e.Message);
}
}
}
}
}

}

class Contestant
{
public static char[] talentCodes = { 'S', 'D', 'M', 'O' };
public static string[] talentStrings = {"Singing", "Dancing",
"Musical instrument", "Other"};
public string Name { get; set; }
private char talentCode;
private string talent;
private int entryFee;

public char TalentCode
{
get
{
return talentCode;
}
set
{
int pos = talentCodes.Length;
for (int x = 0; x < talentCodes.Length; ++x)
if (value == talentCodes[x])
pos = x;
try
{
if (pos == talentCodes.Length)
{
throw new Exception("Invalid");
}
else
{
talentCode = value;
talent = talentStrings[pos];
}
}
catch(Exception e)
{
talentCode = 'I';
talent = e.Message;
}
}

}
public string Talent
{
get
{
return talent;
}
}

public int EntryFee
{
get
{
return entryFee;
}
set
{
entryFee = value;
}

}
}

  
  
class ChildContestant : Contestant
{
public ChildContestant()
{
EntryFee = 15;
}
public override string ToString()
{
return "\n Name: " + Name + "\n Talent Code: " + TalentCode +
"\n Talent Description: " + Talent + "\nEntry Fee: " + EntryFee +
"\nAge Category: Child";
}
}   
  
class TeenContestant : Contestant
{
public TeenContestant()
{
EntryFee = 20;
}
public override string ToString()
{
return "\n Name: " + Name + "\n Talent Code: " + TalentCode +
"\n Talent Description: " + Talent + "\nEntry Fee: " + EntryFee +
"\nAge Category: Teen";
}
}
  
  
class AdultContestant : Contestant
{
public AdultContestant()
{
EntryFee = 30;
}
public override string ToString()
{
return "\n Name: " + Name + "\n Talent Code: " + TalentCode +
"\n Talent Description: " + Talent + "\nEntry Fee: " + EntryFee +
"\nAge Category: Adult";
}
}