quicksort.js

// quicksort sorting algorithm, in 2 lines of code

let quicksort = ([a, ...as]) => {
    if (a == null) return as
    return quicksort(as.filter(x => x <= a))
      .concat([a])
      .concat(quicksort(as.filter(x => x > a)))
}
    
let test1 = [5,1,2,3,5,6];
let test2 = ['c', 'a', 'm', 'b', 'd', 'p']
let test3 = []

console.log(quicksort(test1)) // [1,2,3,4,5,6]
console.log(quicksort(test2)) // ['a', 'b', 'c', 'd', 'm', 'p']
console.log(quicksort(test3)) // []