C# Basics: Bonus Exercises (Arithmetic Calculator and Averager)

using System;

namespace Treehouse.Averager

{

     class Program

    {

        static void Main(string[] args)

        {

            var runningTotal = 0.0;

            var countEntries = 0;


            while (true)
            {
                Console.Write("Enter a number or type \"done\" to see the average (or type \"quit\" to exit): ");
                var entry = Console.ReadLine();

                if (entry.ToLower() == "done")
                {
                    Console.WriteLine("Average = " + runningTotal / (double)countEntries + " (Enter another number to add it to your average)");
                }
                else if (entry.ToLower() == "quit")
                {
                    break;
                }

                else
                {
                    try
                    {
                        var number = double.Parse(entry);

                        runningTotal += number;

                        countEntries++;

                    }
                    catch (Exception e) when (e is FormatException || e is OverflowException || e is DivideByZeroException)
                    {
                        Console.WriteLine("Please type a valid numeric value");
                        continue; 
                    }
                }

                //Console.WriteLine(countEntries); //ο συνολικός αριθμός εισόδων αριθμών από τον χρήστη για τον υπολογισμό του μέσου όρου

            }
        }
    }
}

using System;


namespace Arithmetic_Calculator
{
    class Program
    {
        static void Main(string[] args)
        {

            string entry;
            string operatorSymbol;
            double nu1;
            double nu2;

            while (true)
            { 
                Console.Write("Enter a number (or type \"quit\" to exit): ");
                entry = Console.ReadLine();
                if (!double.TryParse(entry, out nu1) && entry.ToLower() != "quit")
                {
                    Console.WriteLine("Please type a number or \"quit\"", entry);
                    continue;
                }



                if (entry.ToLower() != "quit")
                { 

                    nu1 = double.Parse(entry);

                    Console.Write("Enter a math operator (or type \"quit\" to exit): ");
                    operatorSymbol = Console.ReadLine();
                    if (operatorSymbol.ToLower() == "quit")
                    {
                        break;
                    }
                    while(true)
                    {
                        if (operatorSymbol != "*" && operatorSymbol != "-" && operatorSymbol != "+" && operatorSymbol != "/" && operatorSymbol != "%" && operatorSymbol !="^")
                        {
                            Console.Write("Please type a valid math operator: ");
                            operatorSymbol = Console.ReadLine();
                        }
                        else
                        {
                            break;
                        }
                    }



                    Console.Write("Enter another number (or type \"quit\" to exit): ");
                    entry = Console.ReadLine();
                    if (!double.TryParse(entry, out nu2) && entry.ToLower() != "quit")
                    {
                        Console.WriteLine("Please type a number", entry);
                        continue;
                    }

                    if (entry.ToLower() == "quit")
                    {
                        break;
                    }

                    nu2 = double.Parse(entry);

                    if (operatorSymbol == "+")
                    {
                        Console.WriteLine("Result is: " + (nu1 + nu2));
                    }
                    else if (operatorSymbol == "-")
                    {
                        Console.WriteLine("Result is: " + (nu1 - nu2));
                    }
                    else if (operatorSymbol == "*")
                    {
                        Console.WriteLine("Result is: " + (nu1 * nu2));
                    }
                    else if (operatorSymbol == "/")
                    {
                        Console.WriteLine("Result is: " + (nu1 / nu2));
                    }
                    else if (operatorSymbol == "%")
                    {
                        Console.WriteLine("Result is: " + (nu1 % nu2));
                    }
                    else if (operatorSymbol == "^")
                    {
                        Console.WriteLine("Result is: " + Math.Pow(nu1, nu2));
                    }

                }
                else
                {
                    break;
                }
            }
        }
    }
}