Adding comma as thousands separator (javascript) - output being deleted instead

Question

I am attempting to dynamically adjust a numerical value entered to include thousand separators

Here is my code:

function addCommas(nStr) {
    nStr +         


        

Answer 1

In each case before formatting try to remove existing commas first, like there: Removing commas in 'live' input fields in jquery

Example:

function addThousandsSeparator(x) {
    //remove commas
    retVal = x ? parseFloat(x.replace(/,/g, '')) : 0;

    //apply formatting
    return retVal.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}