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
    Animated 3D Flipping Menu with CSS

    CSS animations aren't just for basic fades or sliding elements anymore -- CSS animations are capable of much more.  I've showed you how you can create an exploding logo (applied with JavaScript, but all animation is CSS), an animated Photo Stack, a sweet...

  • 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
    CSS Tooltips

    We all know that you can make shapes with CSS and a single HTML element, as I've covered in my CSS Triangles and CSS Circles posts.  Triangles and circles are fairly simply though, so as CSS advances, we need to stretch the boundaries...

  • By
    Create a Photo Stack Effect with Pure CSS Animations or MooTools

    My favorite technological piece of Google Plus is its image upload and display handling.  You can drag the images from your OS right into a browser's DIV element, the images upload right before your eyes, and the albums page displays a sexy photo deck animation...

Discussion

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