.Net 4.0 Optimized code for refactoring existing “if” conditions and “is” operator

Question

I have following C# code. It works fine; but the GetDestination() method is cluttered with multiple if conditions by using is operator.

In

Answer 1

Approach 1 (Selected): Using dynamic keyword to implement multimethods / double dispatch

Approach 2: Use a dictionary to avoid if blocks as mentioned in Jon Skeet’s answer below.

Approach 3: Use a HashList with delegates if there is condition other than equality (For example, if input < 25). Refer how to refactor a set of <= , >= if...else statements into a dictionary or something like that

Apporach 4: Virtual Functions as mentioned in MarcinJuraszek’s answer below.

MultiMethods / Double Dispatch approach using dynamic keyword

Rationale: Here the algorithm changes based on the type. That is, if the input is Accountant, the function to be executed is different than for Manager.

    public static class DestinationHelper
    {
        public static string GetDestinationSepcificImplm(Manager x)
        {
            return @"\ManagerHome";
        }

        public static string GetDestinationSepcificImplm(Accountant x)
        {
            return @"\AccountantHome";
        }

        public static string GetDestinationSepcificImplm(Cleaner x)
        {
            return @"\CleanerHome";
        }
    }

   class Program
    {
        static string GetDestination(Role x)
        {

            #region Other Common Works
            //Do logging
            //Other Business Activities
            #endregion

            string destination = String.Empty;
            dynamic inputRole = x;
            destination = DestinationHelper.GetDestinationSepcificImplm(inputRole);
            return destination;
        }

        static void Main(string[] args)
        {
            string destination = GetDestination(new Security());
            Console.WriteLine(destination);
            Console.WriteLine("....");
            Console.ReadLine();
        }

    }