Haskell is a really neat language! In fact, you can implement quicksort in just one line.
While this is tremendously inefficient, I thought it would be fun to create a JS version of the one-liner, should I ever need it in an interview.
const quicksort = ([h, ...arr]) => [h, ...arr].length
? [ ...quicksort(arr.filter(a => h >= a)), h,
...quicksort(arr.filter(a => h < a)) ]