|Perl: the Markov chain saw|
Re^3: OOP's setter/getter method - is there a way to avoid them?by BrowserUk (Patriarch)
|on Nov 04, 2015 at 20:18 UTC||Need Help??|
What you're saying, in short, is to take responsibility for implementing the actions taken on your object rather than foisting that responsibility onto code outside the object?
Yes, but also more than that.
The use of accessors & mutators does not necessarily imply that. For example, my BankAccount example might be implemented something like this:
But the point to note here is that getBalance() & setBalance() serve no purpose. There is no purpose in performing any further validity testing within those methods as they should never be called from outside; and whenever they are called from inside, all validity checking required or possible should have already taken place.
So every use of those methods can be directly and correctly substituted with inlined, direct access to the object attributes; thus they are pure overhead for no benefit; and with the very great downside of breaking encapsulation by exposing the internal attributes to the outside world via the very accessors that are apparently intended to ensure it!
The same applies to pretty much all other accessors and mutators, with the very rare exception of when it makes sense to have classes of objects that are nothing more that bags of associated variables. And I do mean, very rare.
There are only two arguments that even vaguely make sense for the provision of accessors:
To date, and I've been arguing this point for most of my career, the provision of externally accessible accessors and mutators is a direct contravention of the design goals and aspirations of OO design. And the use of internal use only accessors and mutators -- where the language allows this -- is pure avoidable overhead with only a theoretical potential benefit that in 30 years I've never seen realised.
In compiled languages with decent optimising compilers; that overhead is minimal as the accessors and mutators get in-lined at compile time; but in a interpreted languages without that benefit and without a mechanism to prevent those accessors being used externally to the class; they are not just overhead, but severe code-smell.
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
In the absence of evidence, opinion is indistinguishable from prejudice.