My personal little JavaScript WTF

There are presentations and even a website dedicated to JavaScript oddities. I'm sure this one I ran into has been discussed before, but it certainly surprised me.

I wrote a little function that I thought was pretty trivial. Given a set of objects, iterate over them, check some value, and if good, append matches to an array. Here is an example of what I wrote.

When I ran my code, I kept getting a 0-length array back. I added a simple variable inside my condition and confirmed that it was matching and appending those matches, so... wtf?

Some of you probably see it right away. It took me a good twenty minutes of frustration before I saw it. See the push call? I used brackets instead of parenthesis. I have no idea why this didn't throw an error and I'd love to know why. Ok, JavaScript gurus, can you explain this one?

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About Raymond Camden

Raymond is a developer advocate for Extend by Auth0. He focuses on serverless and enterprise cat demos. If you like this article, please consider visiting my Amazon Wishlist or donating via PayPal to show your support.

Lafayette, LA