title: type 'String' is not a subtype of type 'List<String>' of 'function result'
body: <p>Declared this : </p>
  
  <pre><code>List&lt;String&gt; _questionText = new List(creatingQuiz.totalQuestionsCount);
  </code></pre>
  
  <p>Executed this : </p>
  
  <pre><code>TextFormField(
              validator: (value) {
                if (value.isEmpty) {
                  return 'Cannot be empty';
                } else {
                  _questionText[qCount] = value;
                  return null;
                }
              },
              decoration:
                  InputDecoration(labelText: "Question number $count"),
            ),
  </code></pre>
  
  <p>The list type is string, and value is type string too. 
  still getting this type error :</p>
  
  <pre><code>type 'String' is not a subtype of type 'List&lt;String&gt;' of 'function result'
  </code></pre>
  
  <p>This is the Stack Trace </p>
  
  <pre><code>When the exception was thrown, this was the stack
  #0      _questionText (package:myshipapp/QuizApp/addQuestions.dart)
  #1      _MyHomePageState.question.&lt;anonymous closure&gt; 
          package:myshipapp/QuizApp/addQuestions.dart:94
  #2      FormFieldState._validate 
          package:flutter/…/widgets/form.dart:392
  #3      FormFieldState.validate.&lt;anonymous closure&gt; 
          package:flutter/…/widgets/form.dart:385
  #4      State.setState 
  package:flutter/…/widgets/framework.dart:1233
  </code></pre>