using System;

​

public class Program

{

    public static void Main()

    {

        IsKnownValue(null);

        IsKnownValue(10);

        IsKnownValue("abc");

        IsKnownValue(3.5D);

    }

​

    static bool IsKnownValue(object value)

    {

        switch (value)

        {

            case null:

                Console.WriteLine("null");

                return true;

            case int intVal:

                Console.WriteLine($"Integer: {intVal}");

                return true;

            case bool boolVal:

                Console.WriteLine($"Boolean: {boolVal}");

                return true;

            case string strVal:

                Console.WriteLine($"String: {strVal}");

                return true;

            default:

                Console.WriteLine("Unknown value / type");

                return false;

        }

    }

}