JSFiddle - React, Tailwind, and code Playground

by Göran Andersson

JavaScript

var val = "1,231,231,232,234.";

var s = parseFloat(val.replace(/,/g,'')).toFixed(2);
while (/\d{4}/.test(s)) {
  s = s.replace(/(\d{3}[,.])/,',$1');
}

alert(s);