smallescommonmultiple.js

// Bonfire: Smallest Common Multiple
// Author: @codebubb
// Challenge: http://www.freecodecamp.com/challenges/bonfire-smallest-common-multiple#
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function smallestCommons(arr) {
	var nums = range(arr[0], arr[1]);
	return nums.reduce(lcm);
}

function gcd(a,b){
	return b === 0 ? a : gcd(b, a % b);
}
function lcm(a,b){
	return a * b / gcd(a,b);
}

function range(a,b){
  var arr = [];
  if(a > b) b = [a, a = b][0];
  for(; a<=b; a++) arr.push(a);
  return arr;
}