Avoid writing slow JS code

A couple of rules to improve the performance of your JS code.

What is this ?

• A consice list of rules to aviod writing slow code.
• Concrete use cases for each rule.
• Benchmarking of slow code vs fast alternative.

What this is NOT?

• This is not a guide on algorithms or data structures (although they are very important).
• This is not a guide to write the most performant code (but to avoid writing very slow code).
• This is not for competitive programmers, if you know how to calculate the time complexity of your code, and what malloc is, then you probably don't need this guide.

The rules

1. Avoid nested loops when possible.

• Use a Set. ex: Filter invited guests
• Use an index. ex: Group clients with their orders

2. Avoid creating new objects when possible.

• Mutate the object. ex: Separate odd and even numbers

Yes, those are all the simple rules I could come up with so far. I will add more rules soon :)

Contributing

Feel free to open an issue/PR to add new rules or examples. I will be reviewing them and trying to keep the guide concise and each example focused on a single rule.