```
var intToRoman = function(num) {
if(num < 1 || num > 3999) return "";
var numbers = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
var symbols = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"];
var ret = "";
numbers.forEach(function(value, i) {
if(num > 0) {
if((~~(num/value)) > 0) {
var times = ~~(num / value);
num -= (times * value);
while(times > 0) {
ret += symbols[i];
times--;
}
}
}
});
return ret;
};
```