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. :)
![CSS @supports]()
Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS. What we end up doing is repeating the same properties multiple times with each browser prefix. Yuck. Another thing we...
![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...
![MooTools Equal Heights Plugin: Equalizer]()
Keeping equal heights between elements within the same container can be hugely important for the sake of a pretty page. Unfortunately sometimes keeping columns the same height can't be done with CSS -- you need a little help from your JavaScript friends. Well...now you're...
![dwProgressBar v2: Stepping and Events]()
dwProgressBar was a huge hit when it debuted. For those of you who didn't catch my first post, dwProgressBar is a MooTools 1.2-based progress bar which allows for as much flexibility as possible. Every piece of dwProgressBar can be controlled by CSS...
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.