Integer_to_RomanNumerals.js

function convertToRoman(num) {
	const BASE = {
	'M': 1000,
	'CM': 900,
	'D': 500,
	'CD': 400,
	'C': 100,
	'XC': 90,
	'L': 50,
	'XL': 40,
	'X': 10,
	'IX': 9,
	'V': 5,
	'IV': 4,
	'I': 1
	}
	function quotient(divident, divisor) {
		return divident/divisor;
	}

	function getBase(n) {
		let ret = '';
		let matchKey = 4;
		for(let b in BASE) {
			if(n >= BASE[b]) {
			  matchKey = b;
			  break;
			}
		}
		for(let i=1; i<=quotient(n,BASE[matchKey]); i++) {
			ret += matchKey;	//number of times 
		}
		num = n%BASE[matchKey];	//update num
		return ret;
	}

	let roman = ''; 
	while(num > 0) {
		roman += getBase(num);
	}

	return roman;
}

convertToRoman(408));