freeCodeCamp Challenge Guide: Greatest common divisor

Greatest common divisor


Solution 1 (Click to Show/Hide)
function gcd(a, b) {
  // Recursive use of Euclidean algorithm
  return b == 0 ? a : gcd(b, a % b);

This is an implementation of the Euclidean algorithm, which is used to compute the GCD of two numbers. In each instance of recursion, the original two numbers, a and b, are respectively replaced by b and a % b , which is the remainder of a/b. This continues until the remainder is zero.