← Back toFront-end Tips

Save a few bytes when checking the existence of module

Written byPhuoc Nguyen
Category
Trick
Tags
JavaScript
Created
15 Mar, 2021
Say we are creating a library and want to export our APIs to the consumers. In order to support the CommonJS module, we use the following check:
if (typeof module !== 'undefined') {
module.exports = ourFunction;
}
However, it can be shorten and saved a few bytes when being minified:
if (typeof module < 'u') {
// ...
}
I saw that trick when looking at the Preact's source.

Questions? 🙋

Do you have any questions? Not just about this specific post, but about any topic in front-end development that you'd like to learn more about? If so, feel free to send me a message on Twitter or send me an email. You can find them at the bottom of this page.
I have a long list of upcoming posts, but your questions or ideas for the next one will be my top priority. Let's learn together! Sharing knowledge is the best way to grow 🥷.

Recent posts ⚡

Newsletter 🔔

If you're into front-end technologies and you want to see more of the content I'm creating, then you might want to consider subscribing to my newsletter.
By subscribing, you'll be the first to know about new articles, products, and exclusive promotions.
Don't worry, I won't spam you. And if you ever change your mind, you can unsubscribe at any time.
Phước Nguyễn