CFLib.org – Common Function Library Project

Description:
The RomanFormat function takes a single argument of a positive integer (decimals are truncated, negative numbers will return an empty string, and un-convertable strings will create an error) and returns a string containing the Roman numeral equivalent of the supplied argument.

Return Values:
Returns a string.

Example:

<CFOUTPUT>
&copy; #RomanFormat(Year(now()))# CFLib.org
</CFOUTPUT>

Parameters:

Full UDF Source:

/**
 * Converts a number to Roman numerals.
 * 
 * @param DecIn      Number you want converted to Roman numerals. 
 * @return Returns a string. 
 * @author Brian Kallion (brian@kallion.net) 
 * @version 1, January 29, 2002 
 */
function RomanFormat(DecIn) {

/* declare variables */
var RomOut = ""; // string to be returned
var RomList = "M,D,C,L,X,V,I"; // list of roman numerals
var DecList = "1000,500,100,50,10,5,1"; // list of equivalents to roman numerals

/* variables used in looping */
var i = 1;
var j = 1; 

/* implement the subtraction rule by converting the in strings to the out strings later */
var RomReplaceInList = "DCCCC,CCCC,LXXXX,XXXX,VIIII,IIII";
var RomReplaceOutList = "CM,CD,XC,XL,IX,IV";

/* convert lists to arrays for easier access */
var RomArray = ListToArray(RomList);
var DecArray = ListToArray(DecList);
var RomReplaceInArray = ListToArray(RomReplaceInList);
var RomReplaceOutArray = ListToArray(RomReplaceOutList);

/* hack off the decimal part of the incoming argument */
DecIn = int(DecIn);

/* generate the raw Roman string */
i = 1;
while (DecIn GT 0) {
    if (DecIn - DecArray[i] GTE 0) {
        DecIn = DecIn - DecArray[i];
        RomOut = RomOut & RomArray[i];
        } else {
        i = i + 1;
    }
}

/* apply the subtraction rule to the raw Roman string */
for (j = 1; j LTE ArrayLen(RomReplaceInArray); j = j + 1) {
    RomOut = Replace(RomOut, RomReplaceInArray[j], RomReplaceOutArray[j]);
}

return RomOut;
}