class Program
    {
        static void Main(string[] args)
        {
            int number = 0;

            if (number > 20)
            {
                Console.WriteLine("Number is greater than 20.");
            }
            else if (number < 20)
            {
                Console.WriteLine("Number is less than 20.");
            }
            else
            {
                Console.WriteLine("Number is equal to 20.");
            }

            // Switch - case
            string text = "C#";
            string textConcat = "C#" + "VB.NET";

            Console.WriteLine(textConcat); // Output : C#VB.NET

            switch (text)
            {
                case "VB.NET":
                case "C#":
                    {
                        Console.WriteLine(".NET Compliant Language.");
                        break;
                    }
                case "Java":
                    {
                        Console.WriteLine("Java");
                        break;
                    }
                default:
                    {
                        Console.WriteLine("What is this?");
                        break;
                    }
            }

            // 삼항 연산자. (Conditional Statement)
            bool isJava = (text == "Java") ? true : false;

            // While loop
            int loop = 5;

            while (loop > 0)
            {
                Console.WriteLine("While Loop!");
                loop--;
            }

            loop = 5;

            // do-while loop
            do
            {
                Console.WriteLine("Do-While Loop!");
                loop--;
            } while (loop > 0);

            // for-loop
            for (int i = 0; i < 40; i++)
            {
                Console.WriteLine("For loop!");
            }

            // foreach
            int[] arr = new int[] { 0, 1, 2, 3 };

            foreach (int item in arr)
            {
                Console.WriteLine(item);
            }

            // multi-dimension array
            int[,] twoDimArray = new int[2, 3];
            twoDimArray[0, 2] = 10;
            int num = twoDimArray[0, 1];
        }
    }