Complete roman numeral converter algorithm

Author: ahcode0919

src/fcc-course-projects/fcc_course_projects.md

@@ -5,6 +5,8 @@
 From the Freecodecamp Javascript Certification Algorithms Projects module
 
 - [Palindrome Checker](#palindrome-checker)
+- [Roman Numeral Converter](#roman-numeral-converter)
+- [Caesars Cipher](#caesars-cipher)
 
 #### Palindrome Checker
 
@@ -25,3 +27,27 @@ export function palindrome(str) {
   return normalizedStr === normalizedStr.split('').reverse().join('');
 }
 ```
+
+#### Roman Numeral Converter
+
+Convert the given number into a roman numeral.
+
+All roman numerals answers should be provided in upper-case.
+
+```javascript
+export function convertToRoman(num) {
+  var number = [ 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 ];
+  var numerals = [ 'M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I' ];
+
+  var romanNumeral = '';
+
+  for (var index = 0; index < number.length; index++) {
+    while (number[index] <= num) {
+      romanNumeral += numerals[index];
+      num -= number[index];
+    }
+  }
+
+  return romanNumeral;
+}
+```

src/fcc-course-projects/roman_numeral_converter.js

@@ -0,0 +1,15 @@
+export function convertToRoman(num) {
+  var number = [ 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 ];
+  var numerals = [ 'M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I' ];
+
+  var romanNumeral = '';
+
+  for (var index = 0; index < number.length; index++) {
+    while (number[index] <= num) {
+      romanNumeral += numerals[index];
+      num -= number[index];
+    }
+  }
+
+  return romanNumeral;
+}

tests/fcc-course-projects/roman_numeral_converter.test.js

@@ -0,0 +1,14 @@
+import { convertToRoman, getValues, getHighestPowerOfTen } from "../../src/fcc-course-projects/roman_numeral_converter";
+
+test('should convert numbers to roman numerals', () => {
+  expect(convertToRoman(2)).toBe('II');
+  expect(convertToRoman(4)).toBe('IV');
+  expect(convertToRoman(12)).toBe('XII');
+  expect(convertToRoman(45)).toBe("XLV");
+  expect(convertToRoman(76)).toBe('LXXVI');
+  expect(convertToRoman(100)).toBe('C');
+  expect(convertToRoman(123)).toBe('CXXIII');
+  expect(convertToRoman(778)).toBe('DCCLXXVIII');
+  expect(convertToRoman(1023)).toBe('MXXIII');
+  expect(convertToRoman(3999)).toBe('MMMCMXCIX');
+});