Yet another problem with classes and Icompare

Prime b

Create a class named Friend. Its auto-implemented properties
include those for the Friend's name, phone number,
and three integers that together represent the Friend's
birthday—month, day, and year. Write a program that
declares an array of eight Friend objects and prompts the
user to enter data about eight friends. Display the Friend
objects in alphabetical order by fi rst name. Save the
program as FriendList.cs.
b. Modify the program created in Exercise 9a so that after
the list of Friend objects is displayed, the program
prompts the user for a specifi c Friend's name and the
program displays the Friend's birthday. Display an
appropriate message if the friend the user requests is not
found. Save the program as FriendBirthday.cs.

Questions: If I wanted to switch from array to list (thingy) how would I do that? Also if my program looks bad tell me what looks not good, or what I could have made better. I know, I declared 3 students instead of 8, I just didn't feel like filling in extra 15 rows of info
Also highlighted in red color, what does that method overrides?

My solution:

Friend[] friends = new Friend[3];
string friendName;
int friendNumber;
int friendDateOfBirth;

Console.WriteLine("Please enter information about your 8 friends:\n\n ");

for (int index = 0; index < friends.Length; index++)
{
Console.WriteLine("Details for each friend: ", index + 1);

Console.WriteLine("Enter friends name: ");
friendName = Console.ReadLine();

Console.WriteLine("Enter his phone number: ");
friendNumber = Convert.ToInt32(Console.ReadLine());

Console.WriteLine("Enter his date of birth in the format of mm/dd/yy: ");
friendDateOfBirth = Convert.ToInt32(Console.ReadLine());
friends[index] = new Friend(friendName, friendNumber, friendDateOfBirth);
}

Console.WriteLine("Enter friends name you looking for: ");
string userInput = Console.ReadLine();
for(int index = 0 ; index < friends.Length; index++)
{
if(userInput == friends[index].FriendName)
{
Console.WriteLine(friends[index].DateOfBirth);
}

}
Console.ReadKey();

*************************
public string FriendName { get; set; }
public int PhoneNumber { get; set; }
public int DateOfBirth { get; set; }

public Friend(string FriendName, int PhoneNumber, int DateOfBirth)
{
this.FriendName = FriendName;
this.PhoneNumber = PhoneNumber;
this.DateOfBirth = DateOfBirth;
}
public override string ToString()
{
return string.Format("Friends name: {0}, phone number: {1}, date of birth: {2}.", FriendName, PhoneNumber, DateOfBirth);
}
public int CompareTo(Friend otherFriend)
{
return this.FriendName.CompareTo(otherFriend.FriendName);
}
}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
Apart from a little tidying up of the input code, you program looks pretty good so far.

Of course, you still need to do the following:

1. Change the phone number so it's a string - unless it's a very simple phone system you have there :)

2. Change the date of birth code so that there are 3 integers to store instead of one.

3. Sort the array into alphabetical order.

4. Once the array is sorted, you could use the Array.BinarySearch method to find a friend instead of looking through them individually. For large arrays, this method is much more efficient but it hardly matters for 8 folks.

5. A message needs to be displayed if the friend is not found. You might need to consider here whether to make the search case-insensitive or not.

This isn't a suitable example for using List instead of an array because you're told in advance how many friends there are going to be. However, I've changed the code to demonstrate how you'd do it if you needed to.

The ToString() method overrides the virtual method of that name in System.Object from which all .NET types ultimately inherit. If you don't override it then, by default, ToString() returns the type name.

using System;
using System.Collections.Generic;

class FriendBirthday
{
static void Main()
{
List friends = new List();
string friendName;
int friendNumber;
int friendDateOfBirth;

Console.WriteLine("Please enter information about your 3 friends:\n\n ");

for (int index = 0; index < 3; index++)
{
Console.WriteLine("Details for friend {0}: ", index + 1);

Console.WriteLine("Enter friends name: ");
friendName = Console.ReadLine();

Console.WriteLine("Enter his phone number: ");
friendNumber = Convert.ToInt32(Console.ReadLine());

Console.WriteLine("Enter his date of birth in the format of mm/dd/yy: ");
friendDateOfBirth = Convert.ToInt32(Console.ReadLine());
friends.Add(new Friend(friendName, friendNumber, friendDateOfBirth));

Console.WriteLine(); // space out the input a bit
}

Console.WriteLine("Enter friends name you looking for: ");
string userInput = Console.ReadLine();

for(int index = 0 ; index < friends.Count; index++)
{
if(userInput == friends[index].FriendName)
{
Console.WriteLine(friends[index].DateOfBirth);
break; // no need to go on
}
}

Console.ReadKey();
}
}

class Friend
{
public string FriendName { get; set; }
public int PhoneNumber { get; set; }
public int DateOfBirth { get; set; }

public Friend(string FriendName, int PhoneNumber, int DateOfBirth)
{
this.FriendName = FriendName;
this.PhoneNumber = PhoneNumber;
this.DateOfBirth = DateOfBirth;
}

public override string ToString()
{
return string.Format("Friends name: {0}, phone number: {1}, date of birth: {2}.", FriendName, PhoneNumber, DateOfBirth);
}

public int CompareTo(Friend otherFriend)
{
return this.FriendName.CompareTo(otherFriend.FriendName);
}
}
14y ago
http://www.c-sharpcorner.com/Forums/Thread/156331/month-in-C-Sharp.aspx

Please see the above link.