formatNumberWithComma method
Formats a number in the string with a comma separator (e.g., 1000 -> 1,000).
Implementation
String formatNumberWithComma({String separator = ','}) {
return validate().replaceAllMapped(
RegExp(r'(\d{1,3})(?=(\d{3})+(?!\d))'),
(Match m) => '${m[1]}$separator',
);
}