別の方法でリストにアクセスする方法を理解しようとしています

Question

これは私のクラスの中の私のコードです。私はDisplayQuestionの質問リストにアクセスする方法を理解しようとしています。私はクイズのメニューを表示するprogram.csを持っていて、静的なものは何も持っていません。

public string Question { get; set; } 
public List<string> Choices { get; set; } 
public char[] CorrectChoice = { 'A', 'B', 'C', 'D' }; 
public List<string> Questions { get; set; } 

これらは私のクラス内の私のメソッドです。このクラスの中でこのリストに何度もアクセスする必要があります。

public void NewQuestion() 
{ 
     Questions = new List<string>(); 
     Choices = new List<string>(); 
     Console.WriteLine("Enter the question: "); 
     Questions.Add(Console.ReadLine()); 
     Console.WriteLine("Enter Choice 1 for the question:"); 
     Choices.Add(Console.ReadLine()); 
     Console.WriteLine("Enter Choice 2 for the question: "); 
     Choices.Add(Console.ReadLine()); 
     Console.WriteLine("Enter Choice 3 for the question: "); 
     Choices.Add(Console.ReadLine()); 
     Console.WriteLine("Enter Choice 4 for the question:"); 
     Choices.Add(Console.ReadLine()); 
     // Console.WriteLine("Enter the correct choice(A,B,C,D)"); 


     foreach (string choice in Choices) 
     { 
      Console.WriteLine(); 
      Console.WriteLine(choice); 
     } 
    } 

    public void DisplayQuestions() 
    { 
     foreach(string question in Questions) 
     { 
      Console.WriteLine(); 
      Console.WriteLine(question); 
     } 
    } 

Answer 1

グローバルセクションでnullに宣言して初期化したり、適切なゲッターセッターメソッドでクラスを作成してみてください。

Answer 2

1つのクラスですべてを行うように制限されているとは思わないでください。関心事を別々のクラスに分ける大雑把で冗長な試みでさえ、可読性、保守性、および健全性に役立ちます。それで、あなたは良いコードから離れた思慮深いリファクタリングだけです。

OBJECT指向の言語であるC＃を使用しています。だから、穀物と一緒に行き、オブジェクトを使って抱きしめてください。

using System; 
using System.Collections.Generic; 
using System.Linq; 

namespace Quiz_StackOverflow 
{ 
    class Program 
    { 
     static void Main(string[] args) 
     { 
      var quizGenerator = new QuizGenerator(); 
      var quiz = quizGenerator.GenerateQuiz(); 
      var quizProctor = new QuizProctor(); 
      var grade = quizProctor.ProctorQuiz(quiz); 
      Console.WriteLine(grade.ToString()); 
      Console.WriteLine("Done. Press any key to exit."); 
      Console.ReadKey(); 
     } 
    } 

    public class QuizGenerator 
    { 
     public Quiz GenerateQuiz() 
     { 
      var problems = GenerateProblems(); 
      var quiz = new Quiz() 
      { 
       Problems = problems 
      }; 
      return quiz; 
     } 

     private List<Problem> GenerateProblems() 
     { 
      List<Problem> problems = new List<Problem>(); 
      int numChoices = InputValidator.GetPositiveNumber("Enter number of problems: "); 
      for (int i = 0; i < numChoices; i++) 
      { 
       Problem problem = GenerateProblem(); 
       problems.Add(problem); 
      } 
      return problems; 
     } 

     private Problem GenerateProblem() 
     { 
      var question = GenerateQuestion(); 
      var choices = GenerateChoices(); 
      var answer = GenerateAnswer(choices); 
      var problem = new Problem() 
      { 
       Question = question, 
       Choices = choices, 
       Answer = answer 
      }; 
      return problem; 
     } 

     private string GenerateQuestion() 
     { 
      Console.WriteLine("Enter the question: "); 
      string question = Console.ReadLine(); 
      return question; 
     } 

     private List<string> GenerateChoices() 
     { 
      List<string> choices = new List<string>(); 
      int numChoices = InputValidator.GetPositiveNumber("Enter number of choices for the question: "); 
      for (int i=1; i<=numChoices; i++) 
      { 
       string choice = GenerateChoice(i); 
       choices.Add(choice); 
      } 
      return choices; 
     } 

     private string GenerateChoice(int index) 
     { 
      Console.WriteLine($"Enter Choice {index} for the question: "); 
      string choice = Console.ReadLine(); 
      return choice; 
     } 

     private Answer GenerateAnswer(List<string> choices) 
     { 
      Console.WriteLine("Enter the answer: "); 
      string userChoice = InputValidator.GetUserChoice(new Problem() { Choices=choices }); 
      var answer = new Answer() 
      { 
       Value = userChoice 
      }; 
      return answer; 
     } 
    } 

    public class QuizProctor 
    { 
     public Grade ProctorQuiz(Quiz quiz) 
     { 
      var answers = new List<Answer>(); 
      foreach(Problem problem in quiz.Problems) 
      { 
       Answer answer = ProctorProblem(problem); 
       answers.Add(answer); 
      } 
      Grade grade = quiz.Grade(answers); 
      return grade; 
     } 

     private Answer ProctorProblem(Problem problem) 
     { 
      string userChoice = InputValidator.GetUserChoice(problem); 
      var answer = new Answer() 
      { 
       Value = userChoice 
      }; 
      return answer; 
     } 
    } 

    public class Quiz 
    { 
     public List<Problem> Problems { get; set; } 

     public Grade Grade(List<Answer> answers) 
     { 
      List<Answer> answerKey = Problems.Select(x => x.Answer).ToList(); 
      var rawResults = new List<Tuple<Answer, Answer>>(); 
      for(int i=0; i<answers.Count; i++) 
      { 
       Answer correct = answerKey[i]; 
       Answer provided = answers[i]; 
       rawResults.Add(new Tuple<Answer, Answer>(correct, provided)); 
      } 
      return new Grade(rawResults); 
     } 
    } 

    public class Grade 
    { 
     private List<Tuple<Answer, Answer>> RawResults { get; set; } 
     public decimal Percent 
     { 
      get { return decimal.Divide(RawResults.Count(x => x.Item1.Equals(x.Item2)), RawResults.Count); } 
     } 

     public Grade(List<Tuple<Answer, Answer>> rawResults) 
     { 
      RawResults = rawResults; 
     } 

     public override string ToString() 
     { 
      return string.Format("You scored a {0:P2}.", Percent); 
     } 
    } 

    public class Problem 
    { 
     public string Question { get; set; } 
     public List<string> Choices { get; set; } 
     public Answer Answer { get; set; } 

     public string Prompt() 
     { 
      Func<int, char> numberToLetter = (int n) => 
      { 
       return (char)('A' - 1 + n); 
      }; 

      string prompt = Question; 
      for (int i=0; i<Choices.Count; i++) 
      { 
       string choice = Choices[i]; 
       prompt += $"\n{numberToLetter(i+1)}) {choice}"; 
      } 
      return prompt; 
     } 
    } 

    public class Answer 
    { 
     public string Value { get; set; } 

     public override string ToString() 
     { 
      return Value + ""; 
     } 

     public override bool Equals(object obj) 
     { 
      if (obj == null || GetType() != obj.GetType()) 
      { 
       return false; 
      } 
      return (obj as Answer).Value.Equals(Value); 
     } 

     public override int GetHashCode() 
     { 
      return Value.GetHashCode(); 
     } 
    } 

    public static class InputValidator 
    { 
     public static int GetPositiveNumber(string prompt) 
     { 
      int number = -1; 
      while (number < 0) 
      { 
       Console.Write(prompt); 
       string input = Console.ReadLine(); 
       try 
       { 
        number = int.Parse(input); 
       } 
       catch (Exception) 
       { 
        Console.WriteLine("ERROR: Please input a positive number."); 
       } 
      } 
      return number; 
     } 

     public static string GetUserChoice(Problem problem) 
     { 
      Func<char, int> letterToNumber = (char c) => 
      { 
       if (char.IsLower(c)) 
       { 
        return (int)(c - 'a' + 1); 
       } 
       return (int)(c - 'A' + 1); 
      }; 

      char userChoiceLetter = '_'; 
      while (!char.IsLetter(userChoiceLetter)) 
      { 
       Console.WriteLine(problem.Prompt()); 
       Console.Write("Answer: "); 
       var input = Console.ReadLine(); 
       try 
       { 
        userChoiceLetter = char.Parse(input); 
       } 
       catch (Exception) 
       { 
        Console.WriteLine("ERROR: Please input a letter corresponding to your choice."); 
       } 
      } 
      int answerIndex = letterToNumber(userChoiceLetter) - 1; 
      return problem.Choices[answerIndex]; 
     } 
    } 
} 

あなたはより具体的に `公共の一覧 質問です