Is there a functionality in JavaScript to convert values into specific locale formats?

Question

Is there a built in function of JavaScript to convert a string into a particular locale (Euro in my case)?

E.g. 50.00 should get converted to 50,0

Answer 1

I am working on an international site which deals with multiple currencies.

I didn't want to deal with setting the Locale every time I wanted to display a currency, so instead I made a prototype which formats the currency to the appropriate locale. It is transparent in its conversions so you can customize it to your needs as well.

Number.prototype.formatMoney = function(moneySymbol, decimalCharacter, thousandsCharacter, decimalPlaces, symbolLocation)
{
    var symbolLocation = (symbolLocation == undefined || symbolLocation < 1 || symbolLocation == "begin")?"begin":"end";
    var decimalPlaces = isNaN(decimalPlaces = Math.abs(decimalPlaces)) ? 2 : decimalPlaces;
    var thisNumber = parseFloat(this, decimalPlaces);
    var decimalCharacter = decimalCharacter == undefined ? "." : decimalCharacter;
    var thousandsCharacter = thousandsCharacter == undefined ? "," : thousandsCharacter;
    //var pm = thisNumber < 0 ? "-" : "";
    var pm = "";
    var pmB = thisNumber < 0 ? "(" : "";
    var pmE = thisNumber < 0 ? ")" : "";
    var i = parseInt(thisNumber = Math.abs(+thisNumber || 0)) + "";
    var j = (j = i.length) > 3 ? j % 3 : 0;
    var retString = pmB;
    retString += ((symbolLocation == "begin")?((moneySymbol)?moneySymbol+"":""):"");
    retString += pm;
    retString += (j ? i.substr(0, j) + thousandsCharacter : "")
    retString += i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + thousandsCharacter);
    //alert((decimalPlaces ? decimalCharacter + (Math.ceil(Math.abs(thisNumber - i)*Math.pow(10, decimalPlaces))/Math.pow(10, decimalPlaces)).toFixed(decimalPlaces).slice(decimalPlaces) : "") + '\n' + Math.abs(thisNumber - i).toFixed(6));
    retString += (decimalPlaces ? decimalCharacter + (Math.ceil(Math.abs(thisNumber - i).toFixed(6)*Math.pow(10, decimalPlaces))/Math.pow(10, decimalPlaces)).toFixed(decimalPlaces).slice(decimalPlaces) : "");
    retString += ((symbolLocation == "end")?((moneySymbol)?moneySymbol+"":""):"");
    retString += pmE;
    return  retString;
};
Number.prototype.formatMoneyInternational = function(languageCode, inputCode)
{
    var languageCode = languageCode == undefined ? 'en_us' : languageCode;
    var inputCode = inputCode == undefined ? languageCode : inputCode;
    var currencies = {
        'float':    {'symbol':null,         'symbolPosition': 'end',        'decimal':'.',  'comma': ''},       //Float
        //Arabic - Saudi Arabia ?(1025): Sorry, the server does not support this locale 
        //Arabic - Iraq ?(2049): Sorry, the server does not support this locale 
        //Arabic - Egypt ?(3073): Sorry, the server does not support this locale 
        //Arabic - Algeria ?(5121): Sorry, the server does not support this locale 
        'bg':       {'symbol':' BGN',       'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Bulgarian 
        'ca':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Catalan 
        //Chinese - Traditional (1028): Sorry, the server does not support this locale 
        //Chinese - Simplified (2052): Sorry, the server does not support this locale 
        'cs':       {'symbol':' Kc',        'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Czech 
        'da':       {'symbol':'kr ',        'symbolPosition': 'begin',      'decimal':',',  'comma': '.'},      //Danish 
        'de':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //German - Germany 
        'de_au':    {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //German - Austrian 
        'de_lu':    {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //German - Luxembourg 
        'el':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Greek 
        'en_us':    {'symbol':'$',          'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //English - United States 
        'en_gb':    {'symbol':'£ ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //English - United Kingdom 
        'en_au':    {'symbol':'$ ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //English - Australia 
        'en_ca':    {'symbol':'$',          'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //English - Canadian 
        'en_ie':    {'symbol':'€ ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //English - Irish 
        'es_mx':    {'symbol':'$ ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //Spanish - Mexico 
        'es':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Spanish - International 
        'fi':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Finnish 
        'fr':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //French - France 
        'fr_ca':    {'symbol':' $',         'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //French - Canadian 
        'fr_ch':    {'symbol':'SFr. ',      'symbolPosition': 'begin',      'decimal':'.',  'comma': '\''}, //French - Swiss 
        //Hebrew ?(1037): Sorry, the server does not support this locale 
        'hu':       {'symbol':' Ft',        'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Hungarian 
        'it':       {'symbol':'€ ',         'symbolPosition': 'begin',      'decimal':',',  'comma': '.'},      //Italian - Italy 
        'it_ch':    {'symbol':'&#8355; ',       'symbolPosition': 'begin',      'decimal':'.',  'comma': '\''}, //Italian - Swiss 
        'ja':       {'symbol':'¥ ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': '\''}, //Japanese 
        //Korean (1042): Sorry, the server does not support this locale 
        'nl':       {'symbol':'€ ',         'symbolPosition': 'begin',      'decimal':',',  'comma': '.'},      //Dutch - Netherlands 
        'no':       {'symbol':'kr ',        'symbolPosition': 'begin',      'decimal':',',  'comma': ' '},      //Norwegian 
        'pl':       {'symbol':' zl',        'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Polish 
        'pt_br':    {'symbol':'R$ ',        'symbolPosition': 'begin',      'decimal':',',  'comma': '.'},      //Portuguese - Brazil 
        'pt':       {'symbol':' €',         'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Portuguese - Standard 
        'ro':       {'symbol':' lei',       'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Romanian 
        'ru':       {'symbol':' p.',        'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Russian 
        'hr':       {'symbol':' kn',        'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Croatian 
        'sr':       {'symbol':' Din.',      'symbolPosition': 'end',        'decimal':',',  'comma': '.'},          //Serbian - Latin 
        //'sr': {'symbol':' ???. ', 'symbolPosition': 'end',    'decimal':',',  'comma': '.'},          //Serbian - Cyrillic 
        'sv':       {'symbol':' kr',        'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Swedish 
        //Thai (1054): Sorry, the server does not support this locale 
        'tr':       {'symbol':' TL',        'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Turkish 
        'id':       {'symbol':' Rp.',       'symbolPosition': 'begin',      'decimal':' ',  'comma': '.'},      //Indonesian 
        'uk':       {'symbol':' rpH.',      'symbolPosition': 'end',        'decimal':',',  'comma': ' '},          //Ukranian 
        'be':       {'symbol':' p.',        'symbolPosition': 'end',        'decimal':',',  'comma': ' '},      //Belausian 
        'sl':       {'symbol':' SIT',       'symbolPosition': 'end',        'decimal':',',  'comma': '.'},          //Slovenian 
        'et':       {'symbol':' kr',        'symbolPosition': 'end',        'decimal':'.',  'comma': ' '},      //Estonian 
        'lv':       {'symbol':'Ls ',        'symbolPosition': 'begin',      'decimal':',',  'comma': ' '},      //Latvian 
        'lt':       {'symbol':' Lt',        'symbolPosition': 'end',        'decimal':',',  'comma': '.'},      //Lithuanian 
        //Farsi ?(1065): Sorry, the server does not support this locale 
        //Vietnamese (1066): Sorry, the server does not support this locale 
        'af':       {'symbol':'R ',         'symbolPosition': 'begin',      'decimal':'.',  'comma': ','},      //Afrikaans 
        'fo':       {'symbol':'kr ',        'symbolPosition': 'begin',      'decimal':',',  'comma': '.'}       //Faeroese
    };
    var currencyString = this+"";
    if(currencies[languageCode])
    {
        //alert(currencyString.replace(currencies[inputCode].comma, '').replace(currencies[inputCode].decimal, '.').replace(/[^\d\.\,\-]/g, ''));
        var currencyNumber = parseFloat(currencyString.replace(currencies[inputCode].comma, '').replace(currencies[inputCode].decimal, '.').replace(/[^\d\.\,\-]/g, ''));
        return currencyNumber.formatMoney(currencies[languageCode].symbol, currencies[languageCode].decimal, currencies[languageCode].comma, 2, currencies[languageCode].symbolPosition);
    }
    else
    {
        var currencyNumber = parseFloat(currencyString.replace(currencies['en_us'].decimal, '.').replace(currencies['en_us'].comma, '').replace(/[^\d\.\,\-]/g, ''));
        alert('Error: '  + languageCode + ' country code unknown.');
        return currencyNumber.formatMoney(currencies['en_us'].symbol, currencies['en_us'].decimal, currencies['en_us'].comma, 2, currencies['en_us'].symbolPosition);
    }
}
String.prototype.formatMoneyInternational = Number.prototype.formatMoneyInternational;

Answer 2

For javascript use the accounting library http://openexchangerates.github.io/accounting.js/ Then you can do:

// Default usage:
accounting.formatMoney(12345678); // $12,345,678.00

// European formatting (custom symbol and separators), can also use     options object as second parameter:
accounting.formatMoney(4999.99, "€", 2, ".", ","); // €4.999,99

// Negative values can be formatted nicely:
accounting.formatMoney(-500000, "£ ", 0); // £ -500,000

// Simple `format` string allows control of symbol position (%v = value, %s = symbol):
accounting.formatMoney(5318008, { symbol: "GBP",  format: "%v %s" }); // 5,318,008.00 GBP

Answer 3

The accepted answer from Matt Ball is wrong - dunno why nobody haven't noticed. There is no such function as String.toLocaleString() [ref]! Therefore when Number.toFixed() returns String, the consequent toLocaleString() does nothing. So you won't get localized number, just the product of toFixed() function.

WRONG (don't do it like this):

var i = 1234.123;
alert(i.toFixed(2).toLocaleString() + ' €'); // ALWAYS alerts '1234.12 €' (no locale formatting)

Suggestion how to do it right:

You may use jQuery plugin like NumberFormatter.