using System;

​

public class Program

{

    public static void Main()

    {

        var f = new foo("test");

        var d = new foo(123);

        Console.WriteLine($"{f.pgm is string}");

        Console.WriteLine($"{d.pgm is string}");

    }

}

​

public class foo

{

    public Object pgm

    {

        get;

        set;

    }

​

    public foo(object ob)

    {

        pgm = ob;

    }

}