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Performance matters: the story of a nice JavaScript refactoring
JS Performance
Performance matters: the story of a nice JavaScript refactoring

Learn how every little change can make a difference.

Days ago I was pleasantly surprised by a contribution that a friend of mine ilteoood made to the Orama repository. The post said:
Performance improved by 5%!
I thought, damn, some good developers were working there at Orama, so who knows how he managed to improve the code so much. In a world where everything runs on the cloud, we must take into consideration that an improvement of this type is not a given Faster calculations mean a reduction in costs and therefore a real advantage for the company.
Over the years I have learned to know myself and I must say that I love to delve into things when the topic interests me. So once again I stopped scrolling through LinkedIn feeds and took the time to check the PR. And I saw some interesting things that still stick with me today, after a few weeks away.
I was shocked
There have been several improvements but the one I didn't expect to make such a difference is this: If instead of calculating the length of the array every time inside a loop, I assign it to a variable, the difference is noticeable. I recreate the case here: jsbenchmark

While benchmarks should always be taken with a grain of salt, it is clear in this example that code where the calculation of .length is done only once is faster even if the code is really simple.

Often there is a competition to see who writes the code with less code or variables to feel better than their colleague, I'm speaking for myself too, let's be clear!
Sometimes we stop to reflect on the fact that writing high-performance and quality code does not necessarily mean using the latest JavaScript/TypeScript construct just released but writing the code that allows us to be truly efficient.
If I have made you curious about the other changes that the good ilteoood has made, here is the PR
I hope you liked the article, see you next time.

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