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
    5 Ways that CSS and JavaScript Interact That You May Not Know About

    CSS and JavaScript:  the lines seemingly get blurred by each browser release.  They have always done a very different job but in the end they are both front-end technologies so they need do need to work closely.  We have our .js files and our .css, but...

  • By
    CSS Animations Between Media Queries

    CSS animations are right up there with sliced bread. CSS animations are efficient because they can be hardware accelerated, they require no JavaScript overhead, and they are composed of very little CSS code. Quite often we add CSS transforms to elements via CSS during...

Incredible Demos

  • By
    Select Dropdowns, MooTools, and CSS Print

    I know I've harped on this over and over again but it's important to enhance pages for print. You can do some things using simple CSS but today's post features MooTools and jQuery. We'll be taking the options of a SELECT element and generating...

  • By
    WebKit-Specific Style:  -webkit-appearance

    I was recently scoping out the horrid source code of the Google homepage when I noticed the "Google Search" and "I'm Feeling Lucky" buttons had a style definition I hadn't seen before:  -webkit-appearance.  The value assigned to the style was "push-button."  They are buttons so that...

Discussion

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