static void Main(string[] args) { bool endApp = false; Console.WriteLine("Fraction calculator in C#\r"); Console.WriteLine("-------------------------\n"); while (!endApp) { //First fraction enter and check Console.WriteLine("Enter first fraction:"); string n1 = Console.ReadLine(); int cleanN1; while (!int.TryParse(n1, out cleanN1)) { Console.Write("This is not valid input. Please enter an integer value: "); n1 = Console.ReadLine(); } string d1 = Console.ReadLine(); int cleanD1; while (!int.TryParse(d1, out cleanD1) || cleanD1 == 0) { Console.Write("This is not valid input. Please enter an integer not zero value: "); d1 = Console.ReadLine(); } //Second fraction enter and check Console.WriteLine("Enter second fraction:"); string n2 = Console.ReadLine(); int cleanN2; while (!int.TryParse(n2, out cleanN2)) { Console.Write("This is not valid input. Please enter an integer value: "); n2 = Console.ReadLine(); } string d2 = Console.ReadLine(); int cleanD2; while (!int.TryParse(d2, out cleanD2) || cleanD2 == 0) { Console.Write("This is not valid input. Please enter an integer not zero value: "); d2 = Console.ReadLine(); } //Create objects of Fraction class Fraction a = new Fraction(cleanN1, cleanD1); Fraction b = new Fraction(cleanN2, cleanD2); Console.WriteLine("Choose an operator from the following list:"); Console.WriteLine("\ta - Add"); Console.WriteLine("\ts - Subtract"); Console.WriteLine("\tm - Multiply"); Console.WriteLine("\td - Divide"); Console.Write("Your option? "); string op = Console.ReadLine(); string result = ""; Fraction c; switch (op) { case "a": c = Fraction.Add(a, b); result = a.Output() + "+" + b.Output() + "=" + c.Output(); break; case "s": c = Fraction.Subtract(a, b); result = a.Output() + "+" + b.Output() + "=" + c.Output(); break; case "m": c = Fraction.Multiply(a, b); result = a.Output() + "+" + b.Output() + "=" + c.Output(); break; case "d": c = Fraction.Divide(a, b); result = a.Output() + "+" + b.Output() + "=" + c.Output(); break; default: break; } if (string.IsNullOrEmpty(result)) { Console.WriteLine("This operation will result in a mathematical error.\n"); } else { Console.WriteLine("Result: " + result); } Console.WriteLine("------------------------\n"); Console.Write("Press 'n' and Enter to close the app, or press any other key and Enter to continue: "); if (Console.ReadLine() == "n") { endApp = true; } Console.WriteLine("\n"); } return; }