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!
![Conquering Impostor Syndrome]()
Two years ago I documented my struggles with Imposter Syndrome and the response was immense. I received messages of support and commiseration from new web developers, veteran engineers, and even persons of all experience levels in other professions. I've even caught myself reading the post...
![Designing for Simplicity]()
Before we get started, it's worth me spending a brief moment introducing myself to you. My name is Mark (or @integralist if Twitter happens to be your communication tool of choice) and I currently work for BBC News in London England as a principal engineer/tech...
![Add Styles to Console Statements]()
I was recently checking out Google Plus because they implement some awesome effects. I opened the console and same the following message:
WARNING!
Using this console may allow attackers to impersonate you and steal your information using an attack called Self-XSS.
Do not enter or paste code that you...
![Downloadify: Client-Side File Generation Using JavaScript and Flash]()
The following tools is in its very beta stages and works intermittently. Its so damn useful that I had to show it off now though!
I recently stumbled upon Downloadify, a client-side file generation tool based on JavaScript and Flash ActionScript code. A...
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.
I think the ! is works with call-parentheses too. So it’s not shorter.
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…