Question

Look at the code below and tell me why after calling the function UpdateContext, the variable connection2 don’t have the same hashcode that variable connection1.

When I set the variable connection2 to connection1, both variables have a pointer to the same memory address. But after passing the variable connection1 by ref in the function UpdateContext that modify the pointer with the ‘new’ instruction, the connection1 have a new pointer address but the connection2 is still with the old address.

   class Program
   {
      static void Main(string[] args)
      {
         var connectionInitializer = new ConnectionInitializer();

         connectionInitializer.Initialize();

         Console.ReadLine();
      }
   }

   public class Connection
   {

   }

   public class ConnectionInitializer
   {
      public void Initialize()
      {
         var connection1 = new Connection();
         var connection2 = connection1;

         Console.WriteLine("Connection 1 (Before ref): " + connection1.GetHashCode());
         Console.WriteLine("Connection 2 (Before ref): " + connection2.GetHashCode());

         this.UpdateContext(ref connection1);

         Console.WriteLine("Connection 1 (After ref): " + connection1.GetHashCode());
         Console.WriteLine("Connection 2 (After ref): " + connection2.GetHashCode());
      }

      private void UpdateContext(ref Connection connection)
      {
         connection = new Connection();
      }
   }

Thank you for your help.

Answer 1

connection2 still references the original Connection object. connection1 has been modified to refer to a new Connection object. connection1 and connection2 are not literally the same reference. connection2 is a copy of connection1 and both of these references, for a time, referred to the same object.

These two references are not linked in any meaningful way aside from what they refer to, one is simply a copy of another. Changing the original will not reflect upon the copy.