JavaScript "magic"

strange parts of language...

Why (! + [] + [] + ![]).length is 9 - DEV Community 👩‍💻👨‍💻

(! + [] + [] + ![]).length === 9

https://twitter.com/flaviocopes/status/1150649630767624192

ObservableHQ, JavaScript Notebooks (from creator of D3.js)

Similar to Jupyter Notebooks, a new data visualization tool
from creator(s) of popular D3.js library

Observable

Observable: The User Manual / Observable / Observable

Five-Minute Introduction / Observable / Observable

Demo / Observable / Observable