Learning Perl Objects, References amp;amp; Modules [Electronic resources] نسخه متنی

Chapter 6. Subroutine References

So far, you've seen references to arrays and hashes.
You can also take a reference to a subroutine
(sometimes called a coderef).

Why would you want to do that?
Well, in the same way that taking a reference to an array lets you
have the same code work on different arrays at different times,
taking a reference to a subroutine allows the same code to call
different subroutines at different times. Also, references permit
complex data structures. A reference to a subroutine allows a
subroutine to effectively become part of that complex data structure.

Put another way, a variable or a complex
data structure is a repository of values throughout the program. A
reference to a subroutine can be thought of as a repository of
behavior in a program. The examples in this
section show how this works.