accessing object values using variable as a key

Question

I\'m trying to access a class value by using a variable previously defined in dart, but I keep getting the error the operator [] isn\'t defined for the class

<

Answer 1

You can createn a toMap() function in your Movie class and access properties using [] operator

class Movie {
  String name;
  String actor;
  String producer;

  Map<String, dynamic> toMap() {
    return {
      'name': name,
      'actor' : actor,
      'producer' : producer,
    };
  }
}

Now Movie class properties can be accessed as:

Movie movie = Movie();
movie.toMap()['name'];

Answer 2

You cannot access class members by a string containing their name. (Except with mirrors - outside the scope of this answer.)

You could remove the class altogether and just use a Map<String, String>.

Map<String, String> movie = {
  'movieTitle': 'Toy Story',
  'actor': 'Tom Hanks',
}

You could add some bool methods on the class.

bool hasNoActor() => actor == null;
...
List values = movieList.where((m) => !m.hasNoActor()).toList();

Or, you could pass a lambda to your mapper.

  Movie movieTitle = Movie()
    ..name = 'Toy Story'
    ..actor = 'Tom Hanks';

  Function hasActor = (Movie m) => m.actor != null;
  List values = movieList.where(hasActor).toList();