Error: The method 'map' isn't defined for the class 'Object?'

Question

var questions = [
  {
    'questionText' : 'What\'s your favorite colour? ',
    'answers' : [ 'Green', 'Red', 'Yellow', 'Black'],
  },
];
return MaterialApp(
  home: Scaffold(
    appBar: AppBar(
      title: Text('My second app'),
    ),
    body: Column(
      children: [
        Question(
            questions[_questionIndex]['questionText'] as String
        ),
        **questions[_questionIndex]['answers'].map((answer){
          return Answer('', answer);
          }),**

I tried to put "as String" but nothing worked, the compiler always returns the same error

Answer 1

你需要让dart知道questions[_questionIndex]['answers']是什么，你可以使用as来做到这一点：

(questions[_questionIndex]['answers'] as List<String>).map((answer){

Error: The method 'map' isn't defined for the class 'Object?'

Error: The method 'map' isn't defined for the class 'Object?'

layout

android

object

dart

flutter