'Displaying multiple buttons from a list of questions with multiple options

so I'm trying to display a list of questions with options. A question may have 2 or 3 options. I want to display 3 options from the list.. and I only want it to be displayed if the question has 3 options.

final questionData = <Question>[
  Question(
      questionText: "You like to work with numbers",
      option1: "Yes",
      option2: "No"),
  Question(
      questionText: "Do you love reading poems, history and comics?.",
      option1: "Yes",
      option2: "No",
      option3: "Sometimes"),
  Question(
      questionText: "You enjoy building things and working with your hands?",
      option1: "Yes",
      option2: "No"),

And this is my question model class

class Question {
  String? questionText;
  String? option1;
  String? option2;
  String? option3;
  String? option4;
  String? option5;

  // constructor
  Question(
      {this.questionText,
      this.option1,
      this.option2,
      this.option3,
      this.option4,
      this.option5});
}

I tried this method, but I still have null being displayed to the screen

int _questionNumber = 0;
  var option3 = false;
  late List<Question> questions = questionData;

  // Function
  Widget condition() {

    Widget widget;

    switch (option3) {
      case true:
        widget = Text(
          questions[_questionNumber].option3.toString(),
          style: TextStyle(
            fontSize: 18,
            fontWeight: FontWeight.bold,
          ),
        );
        break;
      case false:
        widget = Container();
        break;
      default:
        widget = Container();
    }

    // Finally returning a Widget
    return widget;
  }

  // check if options are available
  void isAvailable (){
    if (questions[_questionNumber].option3.toString() != null){
      option3 = true;
      notifyListeners();
    }
  }
arraysjsonlistflutterdart


Solution 1:[1]

Inside of your isAvailable function you have the following statement:

questions[_questionNumber].option3.toString() != null

The only important part here is .toString() != null, which is always false. any String != null.

Your variable option3 is already defined as null-possibly String, you should probably just use

String? option3;

And I assume you can and you should just remove the .toString() part in your if statement

questions[_questionNumber].option3 != null

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Maksim Nikolaev

Related Questions