... The runtime has to keep track of all these references. If the variable message disappears (by going out of scope), other variables (such as ref) might still exist. Therefore, the lifetime of ... One feature of the garbage collector is that you don't know, and should not rely upon, the order in which objects will be destroyed. The final point to understand is arguably the most important: ... the object. These guarantees are tremendously useful and free you, the programmer, from tedious housekeeping chores that are easy to get wrong. They allow you to concentrate on the logic of...