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.
![Chris Coyier’s Favorite CodePen Demos]()
David asked me if I'd be up for a guest post picking out some of my favorite Pens from CodePen. A daunting task! There are so many! I managed to pick a few though that have blown me away over the past few months. If you...
![Being a Dev Dad]()
I get asked loads of questions every day but I'm always surprised that they're rarely questions about code or even tech -- many of the questions I get are more about non-dev stuff like what my office is like, what software I use, and oftentimes...
![Unicode CSS Classes]()
CSS class name structure and consistency is really important; some developers camelcase classnames, others use dashes, and others use underscores. One thing I've learned when toying around by HTML and CSS class names is that you can actually use unicode symbols and icons as classnames.
![Duplicate the jQuery Homepage Tooltips Using Dojo]()
The jQuery homepage has a pretty suave tooltip-like effect as seen below:
Here's how to accomplish this same effect using Dojo.
The XHTML
The above HTML was taken directly from the jQuery homepage -- no changes.
The CSS
The above CSS has been slightly modified to match the CSS rules already...
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)