Immediately Executing Functions
JavaScript is full of nifty little tricks to accomplish tasks with less code. One of those tricks is immediately executing functions. We oftentimes see this pattern for executing anonymous functions to limit variable scope:
(function() {
console.log('executed!');
// Do processing here
})();
What many developers don't know is that this code can be shorted by using a ! before the anonymous function:
!function() {
console.log('executed!');
// Do processing here
}()
The function above executes immediately, just as the first snippet did. One caveat: the immediately executing function always returns false. If you desire the result of the anonymous function, you wont want to use this second pattern.
Ben Alman has created an excellent, detailed writeup on the subject and if you want to learn more, be sure to visit his post!
![How I Stopped WordPress Comment Spam]()
I love almost every part of being a tech blogger: learning, preaching, bantering, researching. The one part about blogging that I absolutely loathe: dealing with SPAM comments. For the past two years, my blog has registered 8,000+ SPAM comments per day. PER DAY. Bloating my database...
![9 Mind-Blowing WebGL Demos]()
As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us. Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos. Another technology available...
![WebKit Marquee CSS: Bringin’ Sexy Back]()
We all joke about the days of Web yesteryear. You remember them: stupid animated GIFs (flames and "coming soon" images, most notably), lame counters, guestbooks, applets, etc. Another "feature" we thought we had gotten rid of was the marquee. The marquee was a rudimentary, javascript-like...
![CSS Kwicks]()
One of the effects that made me excited about client side and JavaScript was the Kwicks effect. Take a list of items and react to them accordingly when hovered. Simple, sweet. The effect was originally created with JavaScript but come five years later, our...
Because not quite enough people pulled out their hair on encountering the function(){…}() syntax.
The first is not exactly valid. The right call has the call-parentheses inside the container parentheses.
(function() { ... code ... }())I think the ! is works with call-parentheses too. So it’s not shorter.
> !function(){console.log('asd')} false > !function(){console.log('asd')}() asd true > function(){console.log('asd')}() asd undefined > (function(){console.log('asd')}()) asd undefined >I think such oddities should be removed from the language.
What would ever be the argument for doing this? A Obfuscated Javascript Code Contest?
Why even use such a function? I don’t get it. If you want code to execute immediatly, just write it outside a ‘function’. What’s the point of an anonymous function you can’t call later on for reusability? Or am I missing something?
Encapsulation of vars…