30-seconds-of-code/snippets/gcd.md

gcd

Calculates the greatest common divisor between two or more numbers/arrays.

The helperGcd function uses recursion. Base case is when y equals 0. In this case, return x. Otherwise, return the GCD of y and the remainder of the division x/y.

const gcd = (...arr) => {
  let data = [].concat(...arr);
  const helperGcd = (x, y) => (!y ? x : gcd(y, x % y));
  return data.reduce((a, b) => helperGcd(a, b));
};

gcd(8, 36); // 4