Functional programming with arrays Although JavaScript’s arrays are very capable out of the box, the functional paradigm improves the clarity and maintainability of array code.

I have tried it myself, but I haven't been successful so far.<BR>By the way, I am looking for the index number of the array which is processed (not the value which can be found at that index), and ...

Use popular 'grammar of data' syntax to filter and subset your two-dimensional JavaScript arrays and more. Here's how to use Arquero for data wrangling in Observable JavaScript and Node.js.