Best Practice .Contains C# [closed]

Question

I don't quite know where to post this but C# is not my first language and I am hoping to get someone to nod their head or correct me :)

This works but seems counter intuitive - mostly because I would like to make a list and then say list contains oneCharacter but, for cases like this, it would be excessively wordy.

The only purpose of this sample code is to evaluate whether oneCharacter is in the string "YN" and to ask if there is a better (or more beautiful) way to do this. It is not any more complicated than that.

    void MainGameLoop()
  {
     while(true)
     {
         Console.WriteLine("Randomizing new string ...");
         var randomizedString = RandomizeString(); 
         Console.WriteLine("Please input the value, only first letter of the input will be taken into account");
         var userInput = Console.ReadLine();
         var userCharacter = userInput[0].ToString();

         // Here is the code I'm hoping to sort out.  Is this a reasonable approach within the If condition?
         if(!randomizedString.Contains(userCharacter))
         {
             Console.WriteLine("Sorry, wrong guess.");
         }
         // end code I'm hoping to sort out

         else
         {
             Console.WriteLine("You guessed it!");
         }
     }

  }

Answer 1

I like this question (for no particular reason) so I will answer with an example (OP can put it into the question so it doesn't get closed).

Say, we want to create a game which will randomize a string and user is expected to guess one letter within that string.

 void MainGameLoop()
 {
    while(true)
    {
        Console.WriteLine("Randomizing new string ...");
        var randomizedString = RandomizeString(); 
        Console.WriteLine("Please input the value, only first letter of the input will be taken into account");
        var userInput = Console.ReadLine();
        var userCharacter = userInput[0].ToString();
        // OP's code starts here
        if(!randomizedString.Contains(userCharacter))
        {
            Console.WriteLine("Sorry, wrong guess.");
        }
        // OP's code ends here
        else
        {
            Console.WriteLine("You guessed it!");
        }
    }

 }

Now, my answer:

For me, usage of Contains is okay. It says exactly what you intend to check. In case you are curious, underneath it actually calls (in your case) randomizedString.IndexOf(userCharacter, StringComparison.Ordinal) >=0 which is a search within an array. Additionally, I think you should change the order of logical conditions, using ! is not needed in this case:

if(randomizedString.Contains(userCharacter))
{
        Console.WriteLine("You guessed it!");
}
else
{
        Console.WriteLine("Sorry, wrong guess.");
}

EDIT: One could also argue that in this case it would be better to use IndexOf(Char) since OP needs only one character to check but for me, if performance is not an issue .Contains(string) is more readable than doing

if (randomizedString.IndexOf(someCharacter) != -1) { }

NOTE: if performance would be an issue, one would probably use for loop instead.