addCommas method Null safety
Implementation
String addCommas(String s, bool intToo) {
String r = '';
final int dp = s.indexOf('.');
if (dp > -1) {
r = s.substring(dp);
s = s.substring(0, dp);
}
final String sign;
if (s.startsWith('-')) {
sign = '-';
s = s.substring(1);
} else {
sign = '';
}
while (s.trim().length > commaDistance) {
r = ',${s.substring(s.length - commaDistance)}$r';
s = s.substring(0, s.length - commaDistance);
}
return sign + s + r;
}