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. :)
![Responsive and Infinitely Scalable JS Animations]()
Back in late 2012 it was not easy to find open source projects using requestAnimationFrame() - this is the hook that allows Javascript code to synchronize with a web browser's native paint loop. Animations using this method can run at 60 fps and deliver fantastic...
![Create Namespaced Classes with MooTools]()
MooTools has always gotten a bit of grief for not inherently using and standardizing namespaced-based JavaScript classes like the Dojo Toolkit does. Many developers create their classes as globals which is generally frowned up. I mostly disagree with that stance, but each to their own. In any event...
![Creating Spacers with Flexbox]()
I was one of the biggest fans of flexbox before it hit but, due to being shuffled around at Mozilla, I never had the chance to use it in any practice project; thus, flexbox still seems like a bit of a mystery to me. This greatly...
![Get Slick with MooTools Kwicks]()
When I first saw MooTools graphical navigation, I was impressed. I thought it was a very simple yet creative way of using Flash. When I right-clicked and saw that it was JavaScript, I was floored. How could they achieve such...
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.