Finding the LCM of a range of numbers

Question

I read an interesting DailyWTF post today, \"Out of All The Possible Answers...\" and it interested me enough to dig up the original forum post where it was submitted. This

Answer 1

Here is my answer in JavaScript. I first approached this from primes, and developed a nice function of reusable code to find primes and also to find prime factors, but in the end decided that this approach was simpler.

There's nothing unique in my answer that's not posted above, it's just in Javascript which I did not see specifically.

//least common multipe of a range of numbers
function smallestCommons(arr) {
   arr = arr.sort();
   var scm = 1; 
   for (var i = arr[0]; i<=arr[1]; i+=1) { 
        scm =  scd(scm, i); 
    }
  return scm;
}


//smallest common denominator of two numbers (scd)
function scd (a,b) {
     return a*b/gcd(a,b);
}


//greatest common denominator of two numbers (gcd)
function gcd(a, b) {
    if (b === 0) {  
        return a;
    } else {
       return gcd(b, a%b);
    }
}       

smallestCommons([1,20]);