toString method

  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 representation.

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.


// TODO(cbracken): Use the `MapBase.mapToString()` static method when the
// minimum SDK version of this package has been bumped to 2.0.0 or greater.
String toString() {
  // Detect toString() cycles.
  if (_isToStringVisiting(this)) {
    return '{...}';

  var result = StringBuffer();
  try {
    bool first = true;
    forEach((k, v) {
      if (!first) {
        result.write(', ');
      first = false;
      result.write('$k: $v');
  } finally {
    assert(identical(_toStringVisiting.last, this));

  return result.toString();