Regular Expression Match Groups

By  on  

Regular expressions are incredibly powerful but can be difficult to maintain. They're a skill you learn on the job and, when the suits walk by, make you look incredibly smart if you have a few up on your screen. How can we solve the maintainability problem? With a match groups, as Addy Osmani enlightened me about last week:

https://twitter.com/addyosmani/status/1386031624232456194

Look at the ?<descriptor> pattern, with the descriptor being a meaningful name that you want to give to a give group. With the group usage, you can more intelligently handle match results:

const re = /(?\d{4})-(?\d{2})-(?\d{2})/;
const result = re.exec('2021-04-26');

// Deconstructing from result.groups
const { year, month, day } = result.groups;

// Using array syntax
const [, year, month, day] = result;

The only real downside of using this strategy is that most developers probably don't know about it. You could also complain that it makes the regular expression longer. In the end, however, maintainability rules the day, and I love that Addy shared this tip with us!

Recent Features

  • 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...

  • By
    Convert XML to JSON with JavaScript

    If you follow me on Twitter, you know that I've been working on a super top secret mobile application using Appcelerator Titanium.  The experience has been great:  using JavaScript to create easy to write, easy to test, native mobile apps has been fun.  My...

Incredible Demos

  • By
    Fade Images with MooTools LazyLoad

    I recently received an email from a MooTools developer asking a great question about my LazyLoad class: "I'm using your LazyLoad MooTools plugin (which is great, by the way). I have been trying to figure out how to modify it so that once an image scrolls into...

  • By
    External Site Link Favorite Icons Using MooTools and CSS

    I recently came upon an interesting jQuery article about how you can retrieve all external links within a page, build the address of the site's favorite icon, and place the favorite icon along side the link. I've chosen a different approach which...

Discussion

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