toString method

@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.

Implementation

@override
String toString() {
  var string = '';
  string += cardNumber.isEmpty ? "" : 'Card Number = $cardNumber\n';
  string += cardHolderName?.isEmpty ?? true ? "" : 'Card Holder = $cardHolderName\n';
  string += expiryYear == null ? "" : 'expiryYear = $expiryYear\n';
  string += expiryMonth == null ? "" : 'expiryMonth = $expiryMonth\n';
  return string;
}