C# Need inputs in different lines

Question

I am trying to create a program that is will take letters as input only and not duplicated. I am getting error when i put one letter in an input. This is what i need to do,

Answer 1

I think this more or less does what you want:

var max = 5;
var array = new char[max];
var letters = "abcdefghij";

var count = 0;
while (count < 5)
{
    Console.WriteLine("Please Enter {0} Letters B/W a through j only: ", max);

    var key = Console.ReadKey();
    var read = key.KeyChar

    if (!letters.Contains(read))
    {
        Console.WriteLine("You have entered an incorrect value");
        continue;
    }

    var found = false;
    for (int i = 0; i < count; i++)
    {
        if (array[i] == read)
        {
            found = true;
        }
    }

    if (found)
    {
        Console.WriteLine("You have entered an duplicate value");
        continue;
    }

    array[count++] = read;
}

Console.WriteLine("You have Entered the following Inputs: ");
for (int i = 0; i < array.Length; i++)
{
    Console.WriteLine(array[i]);
}

Console.ReadKey();