If I look at my stats, a lot of people are wondering how to write a singleton class. I already wrote about it before but my old solution exposed the instance of the class so more than one instance could be created thus making it not completly a singleton class.
In short, you can use private variables when you return another scope when declaring a class.
Since the beginning of Ask Dan a javascript question, I received a bunch of questions. Here’s the first one I received. It’s from Andrew Worcester. There seems (to me anyway) to be an overuse of the “new” syntax in libraries. If I create an Ajax object is there a functional benefit to using: “new Ajax.Request(options)” [...]
First of all, since I made the front page of Ajaxian, a lot of new readers joined in. Welcome to all of you. I would also take a moment to explain that Javascript Kata is a technical blog about javascript and though I will talk here and there about ajax, it is not focused on [...]
When I began with object-oriented javascript, I always saw a self here and there without fully understanding what it meant. Self? When you see self in some object-oriented javascript, it’s just mean that the developer is using a closure that will reference the current object via a variable named self. Because self is a variable, [...]
[UPDATE : This post is outdated. Check out the new post on singletons.] Singleton is one of the most common and easiest design pattern. In fact, a lot of designs are wrong just because the developer didn’t know about singletons and design patterns (I could have said : a lot of my designs were wrong [...]
As I said earlier, objects are hash tables of properties and functions so looping throught them is done the same way (weepee!). The “in” statement The in statement must be used in a for loop. Like this : for (var element in allElements). In most of the other languages, the element variable would contain the [...]
YOU CAN’T. As simple as that. Anyway, what is a constant? A constant is a unchangeable variable that throws an error when you try to write in it. Thus, implementing constant in javascript would be against its will to be opened. The magic of javascript resides in the liberty it gives you to change anything [...]
One of the really concept of the object-oriented programming is the class functions but they are also known as static functions (Java, php, C++) or shared functions (.NET). Why using class method? Class methods help you keeping your code clean by centralizing your functions. Example, you create a calendar object that formats a string from [...]
[UPDATE : This post is outdated. Check out the new post on how to create objects.] Javascript is a functional programming language thus having no “real” objects. You can write it the way you want : procedural spag, functional, object or whatever word you know. Why should I write it object-oriented? Because, OO has proven [...]