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!
![Facebook Open Graph META Tags]()
It's no secret that Facebook has become a major traffic driver for all types of websites. Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly. And of course there are Facebook "Like" and "Recommend" widgets on every website. One...
![CSS vs. JS Animation: Which is Faster?]()
How is it possible that JavaScript-based animation has secretly always been as fast — or faster — than CSS transitions? And, how is it possible that Adobe and Google consistently release media-rich mobile sites that rival the performance of native apps?
This article serves as a point-by-point...
![CSS Fixed Positioning]()
When you want to keep an element in the same spot in the viewport no matter where on the page the user is, CSS's fixed-positioning functionality is what you need.
The CSS
Above we set our element 2% from both the top and right hand side of the...
![HTML5 Input Types Alternative]()
As you may know, HTML5 has introduced several new input types: number, date, color, range, etc. The question is: should you
start using these controls or not? As much as I want to say "Yes", I think they are not yet ready for any real life...
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…