Question

Assuming i have the following classes:

Class MainClass
{
   private OtherClass1;
   MainClass()
   {
      OtherClass1 = new OtherClass1();
   }

   void dispose()
   {
      OtherClass1 = null;
   }
}

class OtherClass1
{
   private OtherClass2;
   OtherClass1()
   {
      OtherClass2 = new OtherClass2();
   }
}

class OtherClass2
{
}

If i instatiate MainClass and later call dispose method, does the OtherClass1 gets garbage collected (later on)? Or do i have first to clear the reference to OtherClass2?

Answer 1

In the code as provided, you don’t have to null anything, you can safely remove your dispose() and all will be well.

If your OtherClass1 and/or OtherClass2 are managed resources, ie they implement the IDisposable interface then your code is not good enough. You then will have to chain the Dispose:

class MainClass : IDisposable
{
   private OtherClass1;
   MainClass()
   {
      OtherClass1 = new OtherClass1();
   }

   public void Dispose()
   {
      OtherClass1.Dispose(); 
      // OtherClass1 = null;  // not needed
   }
}