JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>demo</td>
        <td>1000,00</td>
    </tr>
    <tr>
        <td>demo</td>
        <td>2000,00</td>
    </tr>
</table>

JavaScript

/*jQuery formatNumber v0.1.1 | https://github.com/RaphaelDDL/jquery.formatNumber*/
(function (a) {
    a.fn.extend({
        formatNumber: function (b) {
            var c = {
                cents: ".",
                decimal: ","
            }, b = a.extend(c, b);
            return this.each(function () {
                var e, c = b,
                    d = a(this);
                values = a.trim(d.html()), values += "", x = values.split(c.cents), x1 = x[0], x2 = x.length > 1 ? c.cents + x[1] : "";
                e = /(\d+)(\d{3})/;
                while (e.test(x1)) x1 = x1.replace(e, "$1" + c.decimal + "$2");
                d.html(x1 + x2)
            })
        }
    })
})(jQuery)

//produces 29,323,894.23 (e.g. US standard)
$('td').formatNumber({
  cents: '.',
  decimal: ','
});