Question

class Foo
{
    public List<object> mylist;

    public int num;
    public string name;
    public bool isIt;


    public Foo()
    { 
        mylist = new List<object>();
        mylist.Add(num);
        mylist.Add(name);
        mylist.Add(isIt);
    }
}


class Program
{
    static void Main(string[] args)
    {

        Foo my = new Foo();
        my.isIt = true;
        my.mylist[0] = 5;
        my.mylist[1] = "Hello";
        Console.WriteLine("" + my.mylist[2]);  => returns false instead of true
        Console.ReadLine();

    }
}

Answer 1

Assuming that your list will always have an item at index 2:

    private bool _isIt;

    public List<object> mylist;

    public bool isIt{
      get{return _isIt;}
      set{
         _isIt = value;
         myList[2] = value;
       }
     }