Is it more performant to use several for-loops by themself or to delegated the logic to promises?

Question

Following scenario: A function gets 3 arrays of a certain length, each one of those needs to be iterated over to find a matching object. When the object is found, the for-lo

Answer 1

Would using promises be more efficient in this case, since that way all for-loops can be worked at at the same time?

No, because promises don't make anything asynchronous or parallel. They can only be used to observe things that are already asynchronous or parallel.

All that throwing promises at that code would do is change when the main thread blocks and add overhead.

If you need to offload or parallelize long-running computational tasks, look at web workers.