Decimal to Roman Numeral Converter

DecimalToRoman.js

function DecimalToRoman(num) {
  
  if (num <= 0 || num >= 4000) return num;
  
  var roman   = ["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"];
  var decimal = [1000,900,500,400,100,90,50,40,10,9,5,4,1];
  var romanStr = '';
  
  for (var i = 0, limit = roman.length; i < limit; ++i) {
    while (num >= decimal[i]) {
      num -= decimal[i];
      romanStr += roman[i];
    }
  }
  
  return romanStr;
  
}

console.log(convert(36));