Return a Default Value with Promises Using catch

By  on  

Last week I tweeted all of you looking for your best JavaScript Array and Promise tricks, and as always, it didn't disappoint -- I learned quite a bit!

Today's JavaScript Promise trick is brought to you by Claudio Semeraro: how to use catch to set a default value instead of a try/catch:

// Instead of wrapping this block in a try/catch...
const result = await new Promise(
  (resolve, reject) => reject("Because Stone Cold said so")
)
// ...use catch to set the default value (100)
.catch(() => 100);

As a trick I really like what's this brings; as far as readability and maintenance, if you don't know the trick, you might get confused. What do you think?

Recent Features

  • By
    CSS vs. JS Animation: Which is Faster?

    How is it possible that JavaScript-based animation has secretly always been as fast — or faster — than CSS transitions? And, how is it possible that Adobe and Google consistently release media-rich mobile sites that rival the performance of native apps? This article serves as a point-by-point...

  • By
    Interview with a Pornhub Web Developer

    Regardless of your stance on pornography, it would be impossible to deny the massive impact the adult website industry has had on pushing the web forward. From pushing the browser's video limits to pushing ads through WebSocket so ad blockers don't detect them, you have...

Incredible Demos

  • By
    Optimize Your Links For Print Using CSS — Show The URL

    When moving around from page to page in your trusty browser, you get the benefit of hovering over links and viewing the link's target URL in the status bar. When it comes to page printouts, however, this obviously isn't an option. Most website printouts...

  • By
    Spatial Navigation

    Spatial navigation is the ability to navigate to focusable elements based on their position in a given space.  Spatial navigation is a must when your site or app must respond to arrow keys, a perfect example being a television with directional pad remote.  Firefox OS TV apps are simply...

Discussion

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