In general, handling array functions like we’ve seen here, using JavaScript’s built-in functions like map () and filter (), is an excellent application of the power of functional programming.

Strings are objects within the JavaScript language. They are not stored as character arrays, so built-in functions must be used to manipulate their values.

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.