Algorithms in Javascript

Short and beautiful JS functions

Factorial

const fact = (n) => (n ? n * fact(n - 1) : 1);

Euclid's algorithm

Euclid used minus, the modern variant uses modulo.

const gcd = (n, m) => (m ? gcd(m, n % m) : n);

Exp

The natural exponential function. e is its value at the real number 1.

const exp = (x) =>
  Array(99)
    .fill()
    .reduce((e, _, i) => e + x ** i / fact(i), 0);