> > There is a difference between not set and no meaningful value. >
In PHP, there's no such difference for properties. And I think we should be consistent with the existing behavior here. > The former is literally unset(), the latter is null. The only semantics > PHP exposes here is that not set can be upgraded to "no meaningful" value > in form of null with a notice. > > The difference thus is quite minor, but semantically important. > Hence to *set* the value, we need to explicitly set null. > > If we don't do it this way, we won't have a way to explicitly *set* > nullable properties to a value (null in this case). (without explicit unset > in ctor). > > Bob