toString method Null safety

  1. @override
String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string represetion.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.


String toString() {
  var stringBuffer = StringBuffer();
  _map.forEach((key, value) {
    value.forEach((e) => stringBuffer.writeln('$key: $e'));
  return stringBuffer.toString();