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

Incredible Demos

  • By
    Making the Firefox Logo from HTML

    When each new t-shirt means staving off laundry for yet another day, swag quickly becomes the most coveted perk at any tech company. Mozilla WebDev had pretty much everything going for it: brilliant people, interesting problems, awesome office. Everything except a t-shirt. That had to change. The basic...

  • By
    Check All/None Checkboxes Using MooTools

    There's nothing worse than having to click every checkbox in a list. Why not allow users to click one item and every checkbox becomes checked? Here's how to do just that with MooTools 1.2. The XHTML Note the image with the ucuc ID -- that...

Discussion

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