dateAsString method Null safety
Return the Fact.factDay, Fact.factMonth and Fact.factYear as String like so dd/mm/yyyy.
If no Fact.factDay and/or no Fact.factMonth is given, the returned String ommits these fields like so mm/yyyy or yyyy.
Implementation
String dateAsString() {
String ret = "";
if (factDay != 0) {
ret += factDay.toString().padLeft(2, "0") + '/';
}
if (factMonth != 0) {
ret += factMonth.toString().padLeft(2, "0") + '/';
}
if (factYear != 0) {
ret += factYear.toString();
}
return ret;
}