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.
![39 Shirts – Leaving Mozilla]()
In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...
![Create a CSS Flipping Animation]()
CSS animations are a lot of fun; the beauty of them is that through many simple properties, you can create anything from an elegant fade in to a WTF-Pixar-would-be-proud effect. One CSS effect somewhere in between is the CSS flip effect, whereby there's...
![LightFace: Facebook Lightbox for MooTools]()
One of the web components I've always loved has been Facebook's modal dialog. This "lightbox" isn't like others: no dark overlay, no obnoxious animating to size, and it doesn't try to do "too much." With Facebook's dialog in mind, I've created LightFace: a Facebook lightbox...
![Create a 3D Panorama Image with A-Frame]()
In the five years I've been at Mozilla I've seen some awesome projects. Some of them very popular, some of them very niche, but none of them has inspired me the way the MozVR team's work with WebVR and A-Frame project have.
A-Frame is a community project...
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)