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...
![An Interview with Eric Meyer]()
Your early CSS books were instrumental in pushing my love for front end technologies. What was it about CSS that you fell in love with and drove you to write about it?
At first blush, it was the simplicity of it as compared to the table-and-spacer...
![HTML5 Datalist]()
One of the most used JavaScript widgets over the past decade has been the text box autocomplete widget. Every JavaScript framework has their own autocomplete widget and many of them have become quite advanced. Much like the placeholder attribute's introduction to markup, a frequently used...
![MooTools CountDown Plugin]()
There are numerous websites around the internet, RapidShare for example, that make you wait an allotted amount of time before presenting you with your reward. Using MooTools, I've created a CountDown plugin that allows you to easily implement a similar system.
The MooTools JavaScript
The CountDown class...
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.