Roman Numeral Converter 2

General

This script will convert whole numbers to Roman numerals, up to 3,999,999. Easy to use.

Notes

• Created by: Kurt Grigg
• Web Site: http://www.kurtsdhtml.pwp.blueyonder.co.uk/

Source Code

Paste this source code into the designated areas.

External file

Paste this code into an external JavaScript file named: romanNumerals.js

function isValidInput(x){
  var inpt = document.getElementById(“converterinput”);
  if (x == “” || /^s+$/.test(x)){
    alert(‘Empty!nEnter a number to be converted to Roman numerals.’);
    inpt.value = “”;
    inpt.focus();
    return false;
  }
  x = x.replace(/[ ]+/g,””);
  inpt.value = x;
  if (/D+/g.test(x)){
    alert(“Numbers only!nRemoving non-numerical characters…”);
    x = x.replace(/D+/g,””);
    inpt.value = x;
     if (x == “”) {
       alert(‘…no number found after removal.nTry again.’);
       inpt.focus();
       return false;
     }
  }

  if (/^0+$/g.test(x)){
    inpt.value = 0;
    inpt.select();
    alert(‘There is no Roman numeral for zero!nEnter a number from 1 to 3,999,999’);
    return false;
  }

  if (x < 1 || x > 3999999){
    x = x.replace(/^0+/g,””);
    inpt.value = x;
    alert(‘Enter a number from 1 to 3,999,999 only!’);
    inpt.select();
    return false;
  }

  x = x.replace(/^0+/g,””);
  inpt.value = x;
  converter(x);
}

function drawNumerals(n){
  var d = document;
  var temp = d.getElementById(‘converteroutput’);
  temp.firstChild.data = ”;
  var draw = d.createElement(‘span’);
  if (n.toLowerCase() == n){
    draw.style.borderTop = ‘2px solid #000000’;
    draw.style.fontVariant = ‘small-caps’;
  }
  draw.appendChild(d.createTextNode(n));
  temp.appendChild(draw);
}

function converter(e){
  var t = drawNumerals;
  var a = [[1000000,’m’],
  [900000,’cm’],[500000,’d’],[400000,’cd’],[100000,’c’],
  [90000,’xc’],[50000,’l’],[40000,’xl’],[10000,’x’],
  [9000,’M’,’x’],[5000,’v’],[4000,’M’,’v’],[1000,’M’],
  [900,’CM’],[500,’D’],[400,’CD’],[100,’C’],
  [90,’XC’],[50,’L’],[40,’XL’],[10,’X’],
  [9,’IX’],[5,’V’],[4,’IV’],[1,’I’]];
  for (var i = 0; i < a.length;  i++){
    while (e – a[i][0] >= 0){
      t(a[i][1]);
      if (a[i].length == 3){
        t(a[i][2]);
      }
      e -= a[i][0];
    }
  }
}

function resetconverter(){
 var temp = document.getElementById(“converteroutput”);
   while (temp.lastChild.nodeName == ‘SPAN’){
     temp.removeChild(temp.lastChild);
   }
 document.getElementById(“converterinput”).value = “”;
}

function beginConverter(e){
  resetconverter();
  isValidInput(e);
}

Head

Paste this code into the HEAD section of your HTML document.

<script type=”text/javascript” src=”romanNumerals.js”></script>

Body

Paste this code into the BODY section of your HTML document.

<div id=”convertercontainer”>
<div id=”convertertitle”>Numbers To Roman Numerals Converter</div>
Enter a number from 1 to 3,999,999<br>
<input type=”text” id=”converterinput” value=”” autocomplete=”off”> = <span id=”converteroutput”> </span><br>
<input class=”converterbuttons” type=”button” value=”Convert” onclick=”beginConverter(document.getElementById(‘converterinput’).value);this.blur()”>
<input class=”converterbuttons” type=”button” value=”Reset” onclick=”resetconverter();this.blur()”>
</div>