JavaScript: Convert an integer into a Roman Numeral

Last update on April 22 2023 12:19:40 (UTC/GMT +8 hours)

JavaScript Math: Exercise-21 with Solution

Write a JavaScript function that converts an integer into a Roman numeral.

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function that Convert an integer into a Roman Numeral</title>
</head>
<body>

</body>
</html>

Pictorial Presentation:

$JavaScript: Math - Convert an integer into a Roman Numeral.$

JavaScript Code:

function integer_to_roman(num) {
if (typeof num !== 'number') 
return false; 

var digits = String(+num).split(""),
key = ["","C","CC","CCC","CD","D","DC","DCC","DCCC","CM",
"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC",
"","I","II","III","IV","V","VI","VII","VIII","IX"],
roman_num = "",
i = 3;
while (i--)
roman_num = (key[+digits.pop() + (i * 10)] || "") + roman_num;
return Array(+digits.join("") + 1).join("M") + roman_num;
}

console.log(integer_to_roman(27));

Sample Output:

XXVII

Flowchart:

$Flowchart: JavaScript Math- Convert an integer into a Roman Numeral$

Live Demo:

See the Pen javascript-math-exercise-21 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to evaluate binomial coefficients.
Next: Write a JavaScript function that Convert Roman Numeral to Integer.