Algorithm : Find the Digit root of an integer

Digit root of a positive number is the sum of all of its digits.

Finding this Digit root was needed in many problems which were appear in programming contests.
Here is the simplest algorithm(as I think up to now :-) ) to find the Digit root of any positive integer implemented using JavaScript.

function findDigRoot(n) { 
 var root = 0; while (n > 0) { 
  root += n ; 
  n = Math.floor(n / 10); 
 } 
 return root; 
}

Feel free to comment below the post if you have a better, optimized solution or problems regarding the solution.