News for hackers. Stuff that matters.
Re:Show HN: Learn and practice modern JavaScript by Swizec on Thursday January 03, 2019 @10:28AM (#18815763)
https://es6cheatsheet.com aims to do exactly that. Old code on the left, modern alternative on the right.

I didn’t go quite as far back as 1998, but if you kinda know ES5 and older it’s just the right fit.

Re:Show HN: Learn and practice modern JavaScript by chrisweekly on Thursday January 03, 2019 @02:02PM (#18818066)
... or use Babel, learn to write in es6+, and read the es5 output.
Re:Show HN: Learn and practice modern JavaScript by Swizec on Thursday January 03, 2019 @05:14PM (#18819869)
Babel’s output is really really not meant for human consumption.