static void Main(string[] args)
{
//Welcome to Calculator
Console.WriteLine("Hello user! Welcome to calculator.");
Start:
Console.WriteLine("Enter your operation (for instance: 2 + 2):");
//Read user's input
string userInput = Console.ReadLine();
//Validate user's input
Error:
while (string.IsNullOrEmpty(userInput) || Regex.IsMatch(userInput, anyLetter) ||
string.IsNullOrWhiteSpace(userInput) ||
Operations.getOperand(userInput) == ' ')
{
Console.WriteLine();
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Input is incorrect, enter 2 numbers with operations: " +
"\nMultiplication: *\nAddition: +\nDivision: /\nSubstraction: -");
Console.ResetColor();
Console.WriteLine("Enter your operation (for instance: 2 + 2):");
userInput = Console.ReadLine();
}
//Get user's operation
char operand = Operations.getOperand(userInput);
//Get user's numbers
string[] numbers = Operations.getNumbers(userInput, operand);
//Get user's first number
decimal number1 = Operations.getNumber(numbers[0]);
//Get user's Second number
decimal number2 = Operations.getNumber(numbers[1]);
//Check that we do not divide by 0
if (number2 == 0)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("You cannot divide on zero");
userInput = null;
goto Error;
}
//Do calculation with numbers
if (number1 != decimal.MinValue && number2 != decimal.MinValue)
{
Console.WriteLine("Answer is: {0}", Operations.Calc(number1, number2, operand));
Console.WriteLine();
Console.WriteLine("If you want to continue calculations, press Enter");
if (Console.ReadKey(true).Key == ConsoleKey.Enter)
{
goto Start;
}
}
else
{
userInput = null;
goto Error;
}
Console.WriteLine("Thank you for using calculator. Bye!");
}
