JavaScript let's you do proper encapsulation using closures like so:
function Person(name) {
this.setName = function(value) {
name = value;
}
this.getName = function() {
return name;
}
}
There's a memory cost to this, though: every "instance" of the Person
"class" will get it's own set of methods so that:
var joe = new Person('Joe');
var john = new Person('John');
joe.setName === john.setName;
// -> false
You can even use factory functions and drop the "new" and "this"
keywords altogether:
function personFactory(name) {
var person = {};
person.setName = function(value) {
name = value;
}
person.getName = function() {
return name;
}
return person;
}
Experience shows that either of the above solution aren't acceptable,
performance wise, for medium to large applications. There's just too
much time spent in GC.
Best,
Tobie
On Mar 10, 3:27 am, kangax <[email protected]> wrote:
> On Mar 9, 9:50 am, webbear1000 <[email protected]> wrote:
>
>
>
> > I'm interested in your opinions on how I'm handling getters and
> > setters in classes. Can you see any problems with my approach and what
> > trouble might I be getting myself into?
>
> > The huge body of my programming work has been with ASP.NET in VB and
> > C#. So I'm used to classic OOP rather than prototype inheritance. With
> > that in mind, I'm trying to semi-replicate getters and setters
> > thus ...
>
> > ----------------------------------------------------------
> > this.property = function(value){
> > if(arguments.length == 0){
> > return localVariable;
> > }else{
> > localVariable = value;
> > }}
>
> > ----------------------------------------------------------
>
> > So if no arguments are passed, the function becomes a getter or a
> > setter if there are arguments.
>
> > What do you think?
>
> I don't see how prototypal inheritance would not allow you to
> implement property accessors : )
>
> It's easy to do so with either plain javascript:
>
> function Person(name) {
> this.setName(name);}
>
> Person.prototype.getName = function() {
> return this.name;}
>
> Person.prototype.setName = function(name) {
> this.name = name;
>
> }
>
> or using abstraction that Prototype.js provides:
>
> var Person = Class.create({
> initialize: function(name) {
> this.setName(name);
> },
> getName: function() {
> return this.name;
> },
> setName: function(name) {
> this.name = name;
> }
>
> });
>
> I'm not a fan of one-method-accessor API. I like `getXXX`, `setXXX`
> notation more, as it seems to be more descriptive and less error-
> prone. You are obviously free to use whichever you thinks suits
> better.
>
> --
> kangax
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