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. :)
![Write Better JavaScript with Promises]()
You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll...
![Animated 3D Flipping Menu with CSS]()
CSS animations aren't just for basic fades or sliding elements anymore -- CSS animations are capable of much more. I've showed you how you can create an exploding logo (applied with JavaScript, but all animation is CSS), an animated Photo Stack, a sweet...
![CSS Sprites]()
The idea of CSS sprites is pretty genius. For those of you who don't know the idea of a sprite, a sprite is basically multiple graphics compiled into one image. The advantages of using sprites are:
Fewer images for the browser to download, which means...
![jQuery topLink Plugin]()
Last week I released a snippet of code for MooTools that allowed you to fade in and out a "to the top" link on any page. Here's how to implement that functionality using jQuery.
The XHTML
A simple link.
The CSS
A little CSS for position and style.
The jQuery...
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.