using System;
namespace ConsoleCalculator
{
class Calculator
{
static void Main(string[] args)
{
int num1, num2, result;
string op;
Console.Write("Enter the first digit: ");
if (!int.TryParse(Console.ReadLine(), out num1))
{
Console.WriteLine("You must enter a valid integer.");
WaitForIt();
return;
}
Console.Write("Enter the second digit: ");
if (!int.TryParse(Console.ReadLine(), out num2))
{
Console.WriteLine("You must enter a valid integer.");
WaitForIt();
return;
}
Console.Write("Enter an operator (+ or -): ");
op = Console.ReadLine();
if (!Perform(op, num1, num2, out result))
{
Console.WriteLine("You must enter a plus or minus.");
WaitForIt();
return;
}
else
{
Console.WriteLine("The result is: " + result);
WaitForIt();
}
}
private static void WaitForIt()
{
Console.Write("Press Enter Key to continue...");
Console.ReadLine();
}
private static bool Perform(string op, int num1, int num2, out int result)
{
switch (op)
{
case "+":
result = num1 + num2;
return true;
case "-":
result = num1 - num2;
return true;
default:
result = 0;
return false;
}
}
}
}