decToBase function
Convert stringDec, the String representation of a decimal value (e.g.
"10"), to another base depending of the value of base (E.g. 16 for
hexadecimal, 2 for binary, etc.).
Implementation
String decToBase(String stringDec, int base) {
var regExp = getBaseRegExp(10);
if (!regExp.hasMatch(stringDec)) return '';
var dec = int.parse(stringDec);
var digits = <int>[];
while (dec > 0) {
final remainder = dec % base;
// '0'-'9' have code unit 48-57, 'A'-'F' have code unit 65-70
digits.add(remainder >= 10 ? remainder + 55 : remainder + 48);
dec = dec ~/ base;
}
if (digits.isEmpty) return '';
return String.fromCharCodes(digits.reversed);
}