Chapter 13. Object Destruction
In the previous two chapters, we looked at basic object creation and manipulation. In this chapter, we'll look at an equally important topic: what happens when objects go away.
As we showed in Chapter 4, when the last reference to a Perl data structure goes away, Perl automatically reclaims the memory of that data structure, including destroying any links to other data. Of course, that in turn may cause Perl to destroy other ("contained") structures as well.
By default, objects work in this manner because objects use the same reference structure to make more complex objects. An object built of a hash reference is destroyed when the last reference to that hash goes away. If the values of the hash elements are also references, they're similarly removed, possibly causing further destruction.