20 December 2011

C# Lesson 20 : Enumerations and the switch Decision Statement

Here, we demonstrate the use of Enumerations because, in the .NET Framework Class Library, properties can often be set only to a predetermined subset of possible values. To illustrate this point, we create our own custom enumeration and then utilize it in a simple application that demonstrates a third Decision statement, the switch.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace UsingSwitch
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Type in a super hero's name to see his nickname:");
            string userValue = Console.ReadLine();

            switch(userValue.ToUpper())
            {
                case "BATMAN":
                    Console.WriteLine("Caped Crusader");
                    break;
                case "SUPERMAN":
                    Console.WriteLine("Man of Steel");
                    break;
                case "GREENLANTERN":
                    Console.WriteLine("Emerald Knight");
                    break;
                default:
                    Console.WriteLine("Does not compute");
                    break;
            }


            Console.ReadLine();

        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace UnderstandingEnumerations
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.ForegroundColor = ConsoleColor.DarkRed;
            //Console.WriteLine("Hello world!");

            Console.WriteLine("Type in a superhero's name to see his nickname: ");
            string userValue = Console.ReadLine();

            SuperHero myValue;

            if (Enum.TryParse<SuperHero>(userValue, true, out myValue))
            {
                switch (myValue)
                {
                    case SuperHero.Batman:
                        Console.WriteLine("Caped crusader");
                        break;
                    case SuperHero.Superman:
                        Console.WriteLine("Man of Steel");
                        break;
                    case SuperHero.GreenLantern:
                        Console.WriteLine("Emerald Knight");
                        break;
                    default:
                        break;
                }
            }
            else
            {
                Console.WriteLine("Does not compute");
            }

            Console.ReadLine();
        }
    }

    enum SuperHero
    {
        Batman,
        Superman,
        GreenLantern
    }

}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ComplexIfStatement
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Pick a number between 1 and 100:");
            string userValue = Console.ReadLine();

            int compareValue = int.Parse(userValue);

            if ((compareValue < 1) || (compareValue > 100))
                Console.WriteLine("The number you chose was out of bounds.");
            else if ((compareValue == 42) || (compareValue > 90))
                Console.WriteLine("You found one of the special numbers!");
            else
                Console.WriteLine("You didn't find one of the special numbers");

            Console.ReadLine();

        }
    }
}
Source : MS Virtual Academy

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