CSS :is

By  on  

There are scores of developers who hate CSS; don't get it, don't want to get it, etc. Most of that is either down to inefficiencies within the language or misunderstanding of how to properly construct a website structure. I mostly love CSS but there are some parts of the language that I always hated, like having to repeat very similar selectors. That's why I was so happy when I saw CSS :is ; a method of avoid duplication within your selector structure!

You all remember this mindless CSS repetition:

section h1,
section h2, 
section h3,
article h1,
article h2,
article h3 {
  /* styles here */
}

I always loathed having to do that -- lots of maintenance cost and bloated CSS files. This is where :is comes to the rescue:

:is(section, article) :is(h1, h2, h3) {
  /* styles here */
}

is: is a perfect summary of how a tiny addition to the CSS language can make a developer's life just a bit easier!

Recent Features

  • By
    7 Essential JavaScript Functions

    I remember the early days of JavaScript where you needed a simple function for just about everything because the browser vendors implemented features differently, and not just edge features, basic features, like addEventListener and attachEvent.  Times have changed but there are still a few functions each developer should...

  • By
    Welcome to My New Office

    My first professional web development was at a small print shop where I sat in a windowless cubical all day. I suffered that boxed in environment for almost five years before I was able to find a remote job where I worked from home. The first...

Incredible Demos

  • By
    prefers-color-scheme: CSS Media Query

    One device and app feature I've come to appreciate is the ability to change between light and dark modes. If you've ever done late night coding or reading, you know how amazing a dark theme can be for preventing eye strain and the headaches that result.

  • By
    TextboxList for MooTools and jQuery by Guillermo Rauch

    I'll be honest with you: I still haven't figured out if I like my MooTools teammate Guillermo Rauch. He's got a lot stacked up against him. He's from Argentina so I get IM'ed about 10 times a day about how great Lionel...

Discussion

  1. Rahul Kumar

    There is two important facts about :is() :-

    1. If one/more selectors passed in it, are invalid then parser will still parse the entire code and apply the mentioned styles to other selectors except the invalid ones.

    2. It does not work with pseudo elements.

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!