https://egghead.io/courses/reduce-data-with-javascript
Most examples for reduce show you how to take an array of numbers and reduce them to a simple sum. Reduce is a great tool for this, but it can do so much more. It is a powerful tool, and essential to functional programming techniques.
This course will dig deep into the Array#reduce in JavaScript and give you a solid understanding to start using it today.
1 03:56 introducing reduce transforming arrays functionally
2 03:59 introducing reduce reducing an array into an object
3
4 04:47 advanced reduce additional reducer arguments
5
6 08:06 advanced reduce flatten flatmap and reduceright
7 08:19 advanced reduce composing functions with reduce
8 06:29 advanced reduce safe nested object inspection