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
    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...

  • By
    Facebook Open Graph META Tags

    It's no secret that Facebook has become a major traffic driver for all types of websites.  Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly.  And of course there are Facebook "Like" and "Recommend" widgets on every website.  One...

Incredible Demos

  • By
    Disable Autocomplete, Autocapitalize, and Autocorrect

    Mobile and desktop browser vendors do their best to help us not look like idiots by providing us autocomplete, autocorrect, and autocapitalize features.  Unfortunately these features can sometimes get in the way;  we don't always want or need the help they provide.  Luckily most browsers allow...

  • By
    iPhone Click Effect Using MooTools or jQuery

    One thing I love about love about Safari on the iPhone is that Safari provides a darkened background effect when you click a link. It's the most subtle of details but just enforces than an action is taking place. So why not implement that...

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!