Question

            Console.WriteLine(used+ "\n"+ extracted[used]);
            switch (extracted[used])
            {
                case "*": result = number1 * number2; break;
                case "/": result = number1 / number2; break;
                case "+": result = number1 + number2; break;
                case "-": result = number1 - number2; break;
                default: Console.WriteLine("Error - Could not assign starting value."); break;
            }
            Console.WriteLine("Marker 3");
            Console.WriteLine(result);

This snippet produces the output:

1

+

Error – Could not assign starting value.

Marker 3

0

Why does this happen? In the second row of the output, the program prints out that the value of extracted[used] is “+”, yet the switch statement fails to go to case “+”, instead going to default, and printing out the error, and then printing out the placeholder value for “result”. If it matters, extracted is an array of strings.

Answer 1

Try switching over extracted[used].Trim() and you’ll get the correct switch to be hit.

Console.WriteLine(used+ "\n<<<"+ extracted[used] + ">>>");
switch (extracted[used].Trim())
{
    case "*": result = number1 * number2; break;
    case "/": result = number1 / number2; break;
    case "+": result = number1 + number2; break;
    case "-": result = number1 - number2; break;
    default: Console.WriteLine("Error - Could not assign starting value."); break;
}
Console.WriteLine("Marker 3");
Console.WriteLine(result);