HackerTube.dev

Monad - FunFunFunction #21

Fun Fun Function · 127.8K views · 2016-02-29 · 11:25

Open on YouTube ↗

If playback is restricted in your region, try opening the original video. Use Mark watched to add it to your marked videos.

Overview

An episode of FunFunFunction explaining monads in JavaScript as functors that also implement flatMap. It builds on the preceding functor episode and works through code examples.

On Hacker News

Recommended to people confused by monads as a friendly, practical explanation for JavaScript developers, with one commenter saying it finally made it click.

Recommended by 3 HN people across 3 months · HN mentions 2016–2021

Topics

Functional programmingWeb development
Search by tags
monadsflatmapfunctorsjavascript

What people said

k__ · 2021-10 · Strong recommendation

I read this example years ago, and it didn't clear anything up for me. After half a year of trying to understand monads, I saw a video by MPJ/Funfunfunction [0] and it finally made sense. [0] [VIDEO]

Read the original HN comment ↗
icc97 · 2018-02 · Recommendation

Here's a half baked explanation, as in just the flatmap part. map is understood in javascript. So you 'just' need to make the leap to flatmap. Which is mapping something and flattening the result. So still you need to learn is what flatten is. But that's not too hard to learn. Try the funfunfunction video [0] [0]: [VIDEO]

Read the original HN comment ↗
intellectable · 2016-07 · Recommendation

I like how mpj explains it. Monad - FunFunFunction #21 [VIDEO] Furthermore, the creator of Elm has a fun explanation too. Evan Czaplicki - Let's be mainstream! User focused design in Elm - Curry On [LINK] More serious computer scientist explains monads in the following. Erik Meijer: Functional Programming [LINK] and here too [LINK]

Read the original HN comment ↗

Sources

Video by Fun Fun Function, played through YouTube.

Data and selection notes

HN summaries and labels may contain AI errors. HN dates refer to discussions, not video publication.

HN Library: HackerTube export (2026-10-31) and open-index/hacker-news. Upstream summaries and classifications may contain AI errors.

Views, duration and playback status refresh separately from the published catalog. When an update fails, existing data remains visible.

Selection checks
  • SaaS & AI candidates: Topic keywords do not match
  • Editor-approved picks: Editorial review is required

Rule matches identify candidates. They do not guarantee video quality or financial results.

About the library and its sources