Question

I’ve seen a lot of example code written using something like (please forgive how horribly canned this is):

public class Test
{
   public object Thingy { get; private set; }
}

Unfortunately, these kinds of examples never really explain why ‘set’ is set as private. So, I’m just wondering if there’s a good, common example that will illustrate to me why something like this would be used.

I sort of see it – the property can be run to process some extra logic in addition to setting that field. I’m just confused on how it would be invoked, and why this approach would be used rather than a generic setter method.

Answer 1

This would be if you have a property that you don’t want anyone to set but your class. This can be handy with database id’s. The internal class can set it but you wouldn’t want anyone else changing it. So you can give them read access but not write.

EDIT: One more point on this is that using what you showed there is helpful for automatic properties. Unfortunately with automatic properties you are unable to only specify get so to avoid exposing a setter publicly it is just made private.

EDIT: Just thought I would throw in an example. Automatic properties are great for clean, terse code. But like you showed there is a limitation in that you have to have get and set. So before it was like this for a property like you showed:

public class Test
{
   private object thingy;
   public object Thingy
   {
      get { return thingy; }
   }
}

Now we can get rid of that unneeded private declaration but it requires both. So make private to get around that.

I know this was overkill on the explanation but different things kept popping in my head.