Convert numbers to Roman numerals

roman.js

var ROM = [
  {key:"M",value:1000},
  {key:"D",value:500},
  {key:"C",value:100},
  {key:"L",value:50},
  {key:"X", value:10},
  {key:"V",value:5},
  {key:"I",value:1}
]
function roman(num){
  var remains = num;
  var ans = ""
  while(remains >= 1000){
    remains -= 1000;
    ans = ans + "M";   
  }
  for (i = 1; i < ROM.length; i++) {
    var part = "";
    while(remains >= ROM[i].value){
      remains -= ROM[i].value 
      part = part + ROM[i].key
      // 4
      if (part.length === 4){
        part = ROM[i].key + ROM[i-1].key
      }
      // 9
      if(i%2 ==1){
        var check = remains - ROM[i].value + ROM[i+1].value
        if (check >= 0){
          part = ROM[i+1].key + ROM[i-1].key
          remains = check
        }
      }
    }
    ans = ans + part
  }
  return ans
}

function convertToRoman(num) {
if (num === 0) return "";
var associativeArray = {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};
for (var i in associativeArray) {
if (num >= associativeArray[i]) `
num = i + convertToRoman(num - associativeArray[i]);
return num;
}
}
}
console.log("Roman:",convertToRoman(68));