Convert arguments to Array
The arguments object thats automatically available within functions can be a source of confusion for some people; it's kind of an array but it's kinda not. JavaScript is awesome in that you can pass any number of arguments to a function, and oftentimes developers need to iterate over every argument provided. The arguments object doesn't have a forEach method, but using a quick JavaScript technique, you can convert arguments to an array:
function myFn(/* any number of arguments */) {
var args = Array.prototype.slice.call(arguments);
// or [].slice.call(arguments)
args.forEach(function(arg) {
// do something with args here
});
}
Much like converting a NodeList to an array, Array's slice method takes the arguments object and converts it to a true array, allowing for forEach, map, and traditional array iteration. Keep that trick up your sleeve for future development.
-
![Detect DOM Node Insertions with JavaScript and CSS Animations]()
I work with an awesome cast of developers at Mozilla, and one of them in Daniel Buchner. Daniel's shared with me an awesome strategy for detecting when nodes have been injected into a parent node without using the deprecated DOM Events API.
-
![Send Text Messages with PHP]()
Kids these days, I tell ya. All they care about is the technology. The video games. The bottled water. Oh, and the texting, always the texting. Back in my day, all we had was...OK, I had all of these things too. But I still don't get...
-
![Animated AJAX Record Deletion Using Dojo]()
I'm a huge fan of WordPress' method of individual article deletion. You click the delete link, the menu item animates red, and the item disappears. Here's how to achieve that functionality with Dojo JavaScript. The PHP - Content & Header The following snippet goes at the...
-
![Introducing LazyLoad 2.0]()
While improvements in browsers means more cool APIs for us to play with, it also means we need to maintain existing code. With Firefox 4's release came news that my MooTools LazyLoad plugin was not intercepting image loading -- the images were loading regardless of...
If you’re using Firefox, or in the future when other browsers support ES6, you can do it more elegantly:
function myFn(...args) { /* code */ }In case you are using Mootools,
Array.fromdoes the job, isn’t it ?Why not it:
You can do that but be aware if you do something like:
function x(){ return Array.apply(null, arguments); }; x(10); //=> it will return empty array with a length of 10 instead of [10]Cool trick, but why even
typeof argumentsreturnsobject?We have a new method,
Array.from(arguments)