If you prefer doing things manually (say you’re not targeting multiple locales), here’s a basic approach using toFixed and some string trickery:
function formatCurrency(amount) {
return "$ " + amount.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
console.log(formatCurrency(2500)); // $ 2,500.00
While this method doesn’t use Intl, it works well when you need a lightweight javascript format currency approach without relying on built-in internationalization.