Snippet 7: Promotion with exceptions

main.dart

// Promotion works with exceptions as well
// as return statements. Try a null check
// that throws an `Exception` instead of
// returning zero.

int getLength(String? str) {
  // Try throwing here if `str` is null.
  
  return str.length;  
}

void main() {
  print(getLength(null));
}

int? getLength(String? str) {
// Try throwing an exception here if str is null.

try{
return str!.length;
}on Exception catch (e) {
throw('$e.runtimeType.toString() $e.message');
}
}

void main() {
print(getLength(null));
}