What's the purpose of an ivar when a property exists?

Question

The following doesn\'t complain at compilation nor runtime about no name ivar. So why is it so common to see an ivar and @property/@synthesize

Answer 1

Two not-so-good-but-necessary reasons to make sure properties are backed up by ivars:

1. For some reason the XCode debugger doesn't show properties that don't have corresponding ivars explicitly declared.
2. It seems to me that under some circumstances using @property without an ivar can hide other ivars, resulting in compilation errors (see Why does a subclass @property with no corresponding ivar hide superclass ivars? )

Unless I've got the wrong ends of a couple of sticks here, I think the use of @property without explicit ivars may lead to annoyances not warranted by the convenience.