To use getters/setters or not to user getters/setters, oh what a question…
I recently read a nice little article by Darron Schall (http://www.darronschall.com/weblog/archives/000149.cfm ) discussing the uselessness of getters and setters, and, after giving it some thought, I have to agree with him. The basic premise of a getter/setter is to you give access to a private property within your class, thus allowing a user of that class to alter the state of that property without knowing about or interfering with any other piece of the class. So Darron’s point is this: why not just use public properties? His point is a valid one. I think that the use of getters and setters is a bit of an old-school method that has become somewhat useless in its’ most basic form. This is not to say that getter/setters are completely useless however. They are still very useful if you want to perform some action on the data the user is setting/getting prior to updating the class or returning a value; however, for simply setting the input value to a private method of the class, there is really no point, and overall it just adds weight (in file size) to your code.
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April 9th, 2008 at 10:17 am
I have to disagree here.
Take the example of a birth date. You may want to do some validation on that birth date. If it is a public property, you can’t.
This would mean that “fred” could be set as the birth date, which isn’t even the right type. It could also mean that the birth date could be a valid date, but in the future.
You might also have properties for which you don’t think you need any validation but for which you might later discover that you do have such a need.
Better to use getters and setters up front then later discover such a problem.
April 9th, 2008 at 3:52 pm
I agree with you on the fact that there are instance when you would want to use them (ex: validation, as I mentioned in my post); however, if you are doing nothing more than taking an argument and storing it in a property there is no difference between using a public property and using a private property with a getter/setter. I guess my main point is that if you have a class with a lot of properties that being set in this fashion, you can save a significant amount of file size by sticking with public properties. If you need validation later, then simply add the get/set methods then…
April 9th, 2008 at 4:47 pm
I liked Darron’s approach too when I read that post.
You can always seamlessly change them to setter/getters later if you need to.
The other thing is that if you’re writing an interface and not a class, then you can’t use public variables, but you can use getters and setters.
April 10th, 2008 at 9:23 am
Darron is right about AS3’s way of implementing getters and setters, it’s really just the long way around setting a property. However, take a look at C++ and you’ll see a hundred good uses for getter and setters. With function and operator overloading, templated classes, pointers and uber-strict data typing conventions, C++ is the sort of language that originated the idea of getters and setters.
AS3 implements getter/setters the way they do because if you are performing mutation or validation on setting/getting a value, the nomenclature for getting/setting a value doesn’t change.
this.myprop = “Blah”;
this code could be using a setter, or could be setting a public property, but the nice thing is, whoever is using my class doesn’t need to know there is a difference. I would hate it if half of a class’s properties were public and half had to be get/set using a function (as is done in C++).
this.myprop = “Blah;
this.setOtherProp(”Blah”); //annoying
April 10th, 2008 at 12:39 pm
This is great guys, I’m really diggin the back and forth and hearing everyones thoughts and ideas! Keep em coming!
May 1st, 2008 at 12:46 pm
I’m just looking forward to ActionScript 5.0. The whole getter/setter argument will be taken care of, trust me. I’m not allowed to tell you any more than that, cos it’s top secret.