JavaScript: Constructor Auto-Execution with new Keyword
JavaScript is full of small, interesting facets that can trip you up, make you laugh, or make you cry. This post is about an interesting one. Those of you that have worked with JavaScript functions, and in a way JavaScript "classes" (as you used with MooTools), you're well acquainted with the new keyword. With the new keyword you get the ability to pass arguments with the function call, but did you know that if you have no arguments, you don't need the parens at all?
function MyClass() {
console.log('Initialized!');
//Set a property, as an example
this.dirty = true;
}
var instance = new MyClass;
// >> "Initialized!''
So why am I telling you this? I have no idea. It's just one of those fun tidbits that you can add to your brain. :)
![Facebook Open Graph META Tags]()
It's no secret that Facebook has become a major traffic driver for all types of websites. Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly. And of course there are Facebook "Like" and "Recommend" widgets on every website. One...
![fetch API]()
One of the worst kept secrets about AJAX on the web is that the underlying API for it, XMLHttpRequest, wasn't really made for what we've been using it for. We've done well to create elegant APIs around XHR but we know we can do better. Our effort to...
![Making the Firefox Logo from HTML]()
When each new t-shirt means staving off laundry for yet another day, swag quickly becomes the most coveted perk at any tech company. Mozilla WebDev had pretty much everything going for it: brilliant people, interesting problems, awesome office. Everything except a t-shirt.
That had to change.
The basic...
![JavaScript Battery API]()
Mozilla Aurora 11 was recently released with a bevy of new features. One of those great new features is their initial implementation of the Battery Status API. This simple API provides you information about the battery's current charge level, its...
Amazing how the obvious is sometimes hidden in plain sight. I was going to save the extra () characters but it looks like there’s a micro performance hit in V8.
http://jsperf.com/new-with-and-without-parens
Really? That’s ironic, since Google Closure Compiler actually removes the parentheses when they can be omitted.
That was something I always was curious about but never bothered to ask/look up. I assume the same thing also occurs in php?
I’ll file this next to optional semi-colons and optional closing tags in HTML5: things that are interesting to know, but if I ever see while reviewing someone’s code I might get stabby.