Arabic to Roman Numeral Coverter

arabic-to-roman-numeral-coverter.js

function arabicToRomanNumeralCoverter(num) {
  if (number === 0) { return ''; }
  const thousands = Math.floor(number / 1000);
  const units = number % 10;
  const tenths = number % 100 - units;
  const hundreds = number % 1000 - tenths - units;
  let inputArr = [thousands, hundreds/100, tenths/10, units];
  
  const romanTenSeq = ["","I","II","III","IV","V","VI","VII","VIII","IX","X"];
  const romanFifty = "L";
  const romanHundred = "C";
  const romanFiveHundred = "D";
  const romanThousand = "M";
  
  let output = '';
  
  // thousands
  while (inputArr[0] > 0) {
    inputArr[0]--;
    output += romanThousand;
  }
  // hundreds
  while (inputArr[1] > 0) {
    if (inputArr[1] === 9) {
      inputArr[1] -= 9;
      output += romanHundred + romanThousand;
    } else if (inputArr[1] >= 5) {
      inputArr[1] -= 5;
      output += romanFiveHundred;
    } else if (inputArr[1] === 4) {
      inputArr[1] -= 4;
      output += romanHundred + romanFiveHundred;
    } else {
      inputArr[1]--;
      output += romanHundred;
    }
  }
  // tenths
  while (inputArr[2] > 0) {
    if (inputArr[2] === 9) {
      inputArr[2] -= 9;
      output += romanTenSeq[10] + romanHundred;
    } else if (inputArr[2] >= 5) {
      inputArr[2] -= 5;
      output += romanFifty;
    } else if (inputArr[2] === 4) {
      inputArr[2] -= 4;
      output += romanTenSeq[10] + romanFifty;
    } else {
      inputArr[2]--;
      output += romanTenSeq[10];
    }
  }
  // units
  while (inputArr[3] > 0) {
    if (inputArr[3] === 9) {
      inputArr[3] -= 9;
      output += romanTenSeq[1] + romanTenSeq[10];
    } else if (inputArr[3] >= 5) {
      inputArr[3] -= 5;
      output += romanTenSeq[5];
    } else if (inputArr[3] === 4) {
      inputArr[3] -= 4;
      output += romanTenSeq[1] + romanTenSeq[5];
    } else {
      inputArr[3]--;
      output += romanTenSeq[1];
    }
  }
  return output;
}

arabicToRomanNumeralCoverter(1000); // M

ArabicToRomanNumeralCoverter.markdown

Arabic to Roman Numeral Converter

Converts the given number from arabic to roman numeral system.

A script by V.

License.