Q:

Console.WriteLine not printing the second argument

I am trying to add two integers using a method in the switch case. I want to show the answer by calling WriteLine, but the result does not show.
static void Main(string[] args)
{        
    Console.WriteLine(
        "Simple Calculator\n\t" +
        " 1) Add\n\t" +
        " 2) Subtract\n\t" +
        " 3) Multiply\n\t" +
        " 4) Divide\n\t" +
        " 5) Quit\n\t", input);

    Console.Write("Enter Selection: ");
    input = Convert.ToInt32( Console.ReadLine());

    switch (input)
    {
        case 1:
            Console.WriteLine("Results:", Add(num1,num2));
            break;
    }          
}

public static double Add(double num1, double num2)
{
  return num1 + num2;
}

A:

Your problem lies in how you are using Console.WriteLine and string formatting.
Console.WriteLine("Result: {0}", Add(num1, num2))

Is what you want.
Read more here.
EDIT @narakaya mentioned you can also take advantage of implicit string casting and just + the two arguments:
Console.WriteLine("Result: " + Add(num1, num2))

