randomNumber.js

function randomNumber(min, max) {
  min = parseInt(min, 10);
  max = parseInt(max, 10);
  if (min !== min) {
    min = 0;
  }
  if (max !== max || max <= min) {
    max = (min || 1) << 1; //doubling
  } else {
    max = max + 1;
  }
  var ratio = Math.random();
  var range = max - min;
 
  return ~~(range * ratio + min); // ~~ coerces to an int, but fast.
}