Enhancing regex of thousands separator?

Question

I saw this beautiful script to add thousands separator to js numbers:

function thousandSeparator(n, sep)
{
    var sRegExp = new RegExp(\'(-?[0-9]+)([0-9]{3         


        

Answer 1

How about this one:

result = "1235423.125".replace(/\B(?=(\d{3})+(?!\d))/g, ',') //1,235,423.125