Question

I use one small code js to add comma to value:

function addCommas(nStr)
{
    nStr += '';
    x = nStr.split('.');
    x1 = x[0];
    x2 = x.length > 1 ? '.' + x[1] : '';
    var rgx = /(\d+)(\d{3})/;
    while (rgx.test(x1)) {
        x1 = x1.replace(rgx, '$1' + ',' + '$2');
    }
    return x1 + x2;
}

I have problem when try to add comma to big values like sextillion values.
Eg.

addCommas(1000000) //return correct "1,000,000"

but if use big values like this

addCommas(50949024266983356472874) // return wrong "5.094902426698335e+22"

What or where I do wrong?

Answer 1

If your number is stored in a string the following function will achieve what you are asking for.

function addCommas( txtNum ) {
    var parts = txtNum.split(".");
    parts[0] = parts[0].reverse().replace(/(\d{3})/g, "$1,").reverse();
    return parts.join(".");
}   

String.prototype.reverse = function () {
    return this.split("").reverse().join("");
}

addCommas( "-50000000000000000000000000000000000000000.0000" );
// => -50,000,000,000,000,000,000,000,000,000,000,000,000,000.0000