ランダムな質問をテキストファイルから配列として表示

Question

私は20の質問があり、テキストファイルから配列として読み込まれるBEDMASテストを行いました。質問をGUIに表示し、その下の入力ボックスに質問に答えます。私は質問を無作為にすることに固執して質問が表示されるようにしますが、同じ質問が同時に表示されることは望ましくありません。それ、どうやったら出来るの。

私のコードは;

import javax.swing.* ; 
import java.text.* ; 
import java.io.* ; 
import java.util.*; 
import java.awt.event.* ; 
import java.util.concurrent.ThreadLocalRandom ; 
/** 
* Date: Jan 2017 
* Description: BEDMAS TEST made up of 20 questions that tests your order of operations skills. 
* Method List: 
* double markCalculator (int input) 
*/ 
public class TheBEDMASTest extends JFrame implements ActionListener { 
      JLabel lblRead, lblPic, lblQuestion, lblBackGnd, lblOutcome ; 
      JTextField txtQuestion, txtAnswer, txtOutcome ; 
      JButton btnNext, btnClear ; 

      static String username = "", mathQuestions [ ] ; 
      static String mathAnswers [ ] ; 
      static int userAnswer = 0 ; 
      static int randomNumbers [ ] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19} ; 
      static int j ; 
      static int m ; 
      static double finalPercent ; 

      NumberFormat percent = NumberFormat.getPercentInstance () ; 


      public TheBEDMASTest() { 
         super ("BEDMAS TEST") ; 

         // Creates Labels 
         lblRead = new JLabel ("Your Answer") ; 
         lblQuestion = new JLabel ("The Question") ; 
         lblPic = new JLabel (new ImageIcon ("orderbedmas.png")) ; 
         lblOutcome = new JLabel ("The Outcome") ; 

         j = m = 0 ; 
         // Creates the TextFields 
         txtQuestion = new JTextField (mathQuestions[j]) ; 
         txtAnswer = new JTextField () ; 
         txtOutcome = new JTextField () ; 

         // Create buttons 
         btnNext = new JButton ("Confirm") ; 
         btnClear = new JButton ("Clear") ; 

         // Set window layout 
         setLayout (null) ; 
         setSize(700, 300) ; 

         lblQuestion.setBounds(10, 15, 150, 15) ; 
         add (lblQuestion) ; 

         lblRead.setBounds(10, 50, 150, 15) ; 
         add (lblRead) ; 

         lblOutcome.setBounds(10, 85, 150, 15) ; 
         add (lblOutcome) ; 

         txtQuestion.setBounds(160, 10, 150, 25) ; 
         add(txtQuestion) ; 

         txtAnswer.setBounds(160, 45, 150, 25) ; 
         add (txtAnswer) ; 

         txtOutcome.setBounds(160, 80, 150, 25) ; 
         add (txtOutcome) ; 

         btnNext.setBounds(70, 175, 120, 70) ; 
         add(btnNext) ; 

         btnClear.setBounds(200, 175, 120, 70) ; 
         add(btnClear) ; 

         lblPic.setBounds(375, 3, 283, 254) ; 
         add(lblPic) ; 

         btnNext.addActionListener (this) ; 
         btnClear.addActionListener (this) ; 

         // Sets the window to visible 
         setVisible(true) ; 
      } 

      public void actionPerformed(ActionEvent evt) { 
         if (evt.getSource () == btnNext) { 
            String phraseOut ; 
            String phraseIn ; 



            phraseIn = txtAnswer.getText() ; 

            phraseOut = correctChecker(phraseIn) ; 
            System.out.println(phraseOut) ; 

            txtOutcome.setText(phraseOut) ; 
            txtQuestion.setText(mathQuestions[j]) ; 
            System.out.println(mathQuestions[j]) ; 
            j++ ; 
            txtQuestion.setText(mathQuestions[j]) ; 
            txtAnswer.setText("") ; 

            if (j == 20) { 
               finalPercent = markCalculator(m) ; 
            } 

         } 

         else if (evt.getSource () == btnClear) { 
            txtAnswer.setText("") ; 
            txtOutcome.setText("") ; 
         } 
      } 

      public static String correctChecker (String mathA) { 

         if (mathA.equalsIgnoreCase(mathAnswers[j])) { 
            m = m+ 1 ; 
            System.out.println(m) ; 
            return "Correct!" ; 

         } 

         else if (mathA.equalsIgnoreCase(mathAnswers[j]) == false) { 
            return "Incorrect!" ; 
         } 

         return "Unknown" ; 
      } 


      public static void main(String[] args) throws IOException { 
         // Declaring variables for question arrays, answers arrays, random number arrays 
//      int k = 0 ; 


         // (needs work) 
         // Shuffle's randomNumbers array 
         shuffleArray(randomNumbers) ; 


         mathQuestions = new String [20] ; 
         mathAnswers = new String [20] ; 

         // Prompts user for name and reads question and array texts 

         // UNCOMMENT 
//      username = IO.readString("What is your name?") ; 

         FileReader fileQ = new FileReader ("mathQuestions.txt") ; 
         BufferedReader input = new BufferedReader (fileQ) ; 

         FileReader fileA = new FileReader ("questionsAnswers.txt") ; 
         BufferedReader input2 = new BufferedReader (fileA) ; 

         for (int i = 0 ; i < mathQuestions.length ; i++) { 
            mathQuestions[i] = input.readLine() ; 
            mathAnswers[i] = input2.readLine() ; 

         } 

         // Prompts user for answer and displays question, checks for correct answer or not 
         for (int j = 0 ; j < mathQuestions.length ; j++) { 

            // (needs work) 
//         k = IO.readInt("" + randomNumbers[j]) ; 

            // UNCOMMENT 
//         userAnswer = IO.readInt(mathQuestions[j]) ; 
//         if (userAnswer == mathAnswers[j]) { 
//            IO.display("Correct!") ; 
//            m = m+ 1 ; 
//         } 
//          
//         else if (userAnswer != mathAnswers[j]) { 
//            IO.display("Incorrect!") ; 
//         } 
         } 

         // Calls mark calculator to calculate and display percent mark 
         finalPercent = markCalculator(m) ; 

//      IO.display(username + "\n" + percent.format(finalPercent)) ; 

         new TheBEDMASTest () ; 

         fileQ.close () ; 
         fileA.close () ; 
      } 

      // Shuffle method (needs work) 
      static void shuffleArray(int[ ] ar) 
      { 
         Random rnd = ThreadLocalRandom.current(); 
         for (int i = ar.length - 1; i > 0; i--) 
         { 
            int index = rnd.nextInt(i + 1); 
            // Simple swap 
            int a = ar[index]; 
            ar[index] = ar[i]; 
            ar[i] = a; 
         } 
      } 

      // Mark calculator method 
      public static double markCalculator (int input) { 
         double userPercent = 0 ; 
         userPercent = (input/20) ; 
         return userPercent ; 
      } 
} 

Answer 1

あなたが一緒にあなたのテストを置くとき、あなたが行うすべてはCollections.shuffle（）を呼び出すで、質問に対応するすべてのインデックスのコレクションを持っている必要があります。次に、ユーザーに質問する質問の数に基づいてループを作成します。

擬似コード

ArrayList<Integer> indices = new ArrayList<>(# of all questions from file); 
for(int index = 0 < index < # of all questions from file; index++) 
    indices.add(index); 

Collections.shuffle(indices); 

for(int question = 0; question < # questions for test; question++) 
    display the Question that corresponds to indices.get(question); 

Example of shuffle