C#: WHILE loop continues, seemingly ignoring the condition

Question

I am writing a basic trivia program to help familiarize myself with C#. I'm in the early stages of development and ran into an issue that I'm having a hard time understanding. Here's the code, followed by what I have tried thus far.

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

namespace TriviaProject
{
    internal class Program
    {
        static void Main(string[] args)
        {

        var q1 = "x";
        int totalCorrect = 0;
        int totalIncorrect = 0;

        Console.WriteLine("Question 1: What is the answer?");
        Console.WriteLine("A. Correct Answer");
        Console.WriteLine("B. Incorrect Answer");
        Console.WriteLine("C. Incorrect Answer");

            while (q1 != "A" || q1 != "B" || q1 != "C")
            {
                q1 = Console.ReadLine();

                switch (q1)
                {
                    case "A":
                        Console.WriteLine("{0} is the correct Answer!", q1);
                        ++totalCorrect;
                        break;

                    case "B":
                        Console.WriteLine("{0} is not correct.", q1);
                        ++totalIncorrect;
                        break;

                    case "C":
                        Console.WriteLine("{0} is not correct.", q1);
                        ++totalIncorrect;
                        break;

                    default:
                        Console.WriteLine("{0} is not a valid entry. A, B or C.", q1);
                        break;
                }
            }
        Console.WriteLine("You got {0} correct and {1} incorrect. Your total score is: ", totalCorrect, totalIncorrect);
        }
    }
}

Desired Behavior If the answer is A, then the totalCorrect tally should increase and be displayed. If the answer is B or C, then the totalIncorrect tally should increase and be displayed.

Tried Thus Far

• If I remove B and C from the WHILE statement, the program works as expect if I answer "A"
• To remedy the above scenario, I added B and C to the WHILE statement assuming I would see similar behavior when answering B and C
• When B and C are included in the While statement, I get the proper feedback (Correct or Incorrect) but the loop continues regardless of what I enter (program never moves on to results)

I have also tried different combinations of using CONTINUE instead of BREAK.

If anyone could explain this behavior, it would be greatly appreciated.

Answer 1

Your while loop is, logically, while (true) .

q1 != "A"

That's false if q1 is A, otherwise it's true

q1 != "B"

That's false if q1 is B, otherwise it's true

Since A is not B, there's no way both of those statements can be false at the same time, so you have

• A) false || true
• B) true || false
• other) true || true

Since true-or-anything is true, your condition is just true .