Convert a number into a Roman Numeral in javaScript

Question

How can I convert integers into roman numerals?

function romanNumeralGenerator (int) {  } 

For example, see the following sample inputs and outputs:

1 = "I" 5 = "V" 10 = "X" 20 = "XX" 3999 = "MMMCMXCIX" 

Caveat: Only support numbers between 1 and 3999

Answer 1

There is a nice one here on this blog I found using google:

http://blog.stevenlevithan.com/archives/javascript-roman-numeral-converter

function romanize (num) {     if (isNaN(num))         return NaN;     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 = "",         i = 3;     while (i--)         roman = (key[+digits.pop() + (i * 10)] || "") + roman;     return Array(+digits.join("") + 1).join("M") + roman; } 

Answer 2

function romanize(num) {   var lookup = {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},roman = '',i;   for ( i in lookup ) {     while ( num >= lookup[i] ) {       roman += i;       num -= lookup[i];     }   }   return roman; } 

^{Reposted from a 2008 comment located at: http://blog.stevenlevithan.com/archives/javascript-roman-numeral-converter}

VIEW DEMO