Question

Using C#

Create an application class named LetterDemo that instantiates objects of two classes named Letter and CertifiedLetter and that demonstrates all their methods.

The classes are used by a company to keep track of letters they mail to clients. The Letter class includes auto-implemented properties for the Name of the recipient and the Date mailed (stored as strings).

Next, include a ToString() method that overrides the Object class’s ToString() method and returns a string that contains the name of the class (using GetType() ) and the Letter’s data field values.

Create a child class named CertifiedLetter that includes an auto-implemented property TrackingNumber (of type string) that holds a tracking number for the letter.

This is the code I'm attempting to run is here:

using System;

class Letter

{
public string Recipin_Name { get; set; }
public string Date { get; set; }
public Letter(string Name, string Mailed)

{

Recipin_Name = Name;

Date = Mailed;

}
public override string ToString()

{

return GetType().ToString() + " " + " Recipient Name : " + Recipin_Name + " Date of Mailing : " + Date;

}
}
class CertifiedLetter : Letter

{
public int TrackingNos { get; set; }
public CertifiedLetter(string Name, string date, int track) : base(Name, date)

{

TrackingNos = track;

}

public override string ToString()

{

return GetType().ToString() + " Recipient Name : " + Recipin_Name + " Date Mailed : " + Date + " " + " Tracking of the Number : " + TrackingNos;

}

}
public class Letterdemo

{
public static void Main()

{

CertifiedLetter Certi = new CertifiedLetter("Electric Company", "02/14/18", 08008);

Console.WriteLine(Certi);

Letter letter = new Letter("Electric Company", "02/14/18");

Console.WriteLine(letter);

}

}

But I get these errors:

Build Failed
Compilation failed: 2 error(s), 0 warnings

NtTestc573ab58.cs(10,24): error CS1729: The type `Letter' does not contain a constructor that takes `0' arguments
LetterDemo.cs(8,12): (Location of the symbol related to previous error)
NtTestc573ab58.cs(11,15): error CS1061: Type `Letter' does not contain a definition for `Name' and no extension method `Name' of type `Letter' could be found. Are you missing an assembly reference?
LetterDemo.cs(3,7): (Location of the symbol related to previous error)

And :

Build Failed
Compilation failed: 2 error(s), 0 warnings

NtTestc9948421.cs(10,24): error CS1729: The type `Letter' does not contain a constructor that takes `0' arguments
LetterDemo.cs(8,12): (Location of the symbol related to previous error)
NtTestc9948421.cs(11,15): error CS1061: Type `Letter' does not contain a definition for `Name' and no extension method `Name' of type `Letter' could be found. Are you missing an assembly reference?
LetterDemo.cs(3,7): (Location of the symbol related to previous error)

Answer 1

Dear Student ,

As per the requirement submitted above , kindly find the below solution.

Here a new Console Application in C# is created using Visual Studio 2017 with name "LetterdemoApp".This application contains a class with name "LetterDemo.cs".Below are the details of this class.

LetterDemo.cs :

//namespace
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//application namespace
namespace LetterdemoApp
{
class Letter //Class Letter
{
//auto-implemented property Name
public string Recipin_Name { get; set; }
//auto-implemented property Date
public string Date { get; set; }
//Constructor
public Letter(string Name, string Mailed)
{
this.Recipin_Name = Name;
this.Date = Mailed;
}
//method ToString()
public override string ToString()
{
return "Type : "+GetType().ToString() + ", " + " Recipient Name : " + Recipin_Name + ", Date of Mailing : " + Date;
}
}
//Class CertifiedLetter
class CertifiedLetter : Letter
{
//auto-implemented property TrackingNos
public int TrackingNos { get; set; }
//Constructor
public CertifiedLetter(string Name, string date, int track) : base(Name, date)
{
this.TrackingNos = track;
}
public override string ToString()
{
return "Type : "+GetType().ToString() + ", Recipient Name : " + Recipin_Name + ", Date Mailed : " + Date + " " + ", Tracking of the Number : " + TrackingNos;
}
}
class LetterDemo //Test class
{
//entry point of application , main method
static void Main(string[] args)
{
//creating object of CertifiedLetter class
CertifiedLetter Certi = new CertifiedLetter("Electric Company", "02/14/18", 08008);
//print details
Console.WriteLine(Certi.ToString());
//creating object of Letter class
Letter letter = new Letter("Electric Company", "02/14/18");
//print details
Console.WriteLine(letter.ToString());
}
}
}

======================================================

Output : Run application using F5 and will get the screen as shown below

Screen 1 :

NOTE : PLEASE FEEL FREE TO PROVIDE FEEDBACK ABOUT THE SOLUTION.