java random array

Question

i would like to make the question random, and when i give the answer to compare if they are correct answer or not?? can someone give me a little help with it?

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Random;

public class Main {

public static void main(String[] args) {


      String[] aa = { "question aa" };
      String[] bb = { "question bb"};
      String[] cc = { "question cc"};
      String[] dd = { "question dd"};

      String[] e = { "answer to question aa" };
      String[] f = { "answer to question bb"};
      String[] g = { "answer to question cc"};
      String[] h = { "answer to question dd"};



     // should be here the random question

      System.out.print("Enter your answer: ");

      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

  String userAnswer = null;

  try {
     userAnswer = br.readLine();
  } catch (IOException ioe) {
     System.out.println("IO error trying to read your answer!");
     System.exit(1);
  }

  System.out.println("Thanks for the answer, " + userAnswer);

}

Answer 1

class QuestionAnswer{
String q;
String a;
//getters/setters and const.
}

1 Create a DS as your Question set is smaller and advisable to keep in memory

List<QuestionAnswer> lst = new ArrayList<QuestionAnswer>();
lst.add(new QuestionAnswer("Question1","Answer1")); 
lst.add(new QuestionAnswer("Question2","Answer2")); 
lst.add(new QuestionAnswer("Question3","Answer3")); 

2 Generate a random integer between 0 to list.size()

Random r = new Random();
int index = r.nextInt(lst.size());

3 Fetch question and print it and accept user;s answer

System.out.println(lst.get(index).getQ());
Scanner in = new Scanner(System.in);
// Reads a single line from the console 
String answer = in.nextLine();

4 Compare user's answer with list

if(answer.equalsIgnoreCase(lst.get(index).getA())){
   System.out.println("You are correct. !!");
} 

Answer 2

• Keep questions in questions array question[][] = {aa,bb...};
• Keep answers in answers array arrays[][] = {e,f...};
• generate random numbers between 0 and questions.length

• questions[random] and answers[random] should match

  String[] aa = { "question aa" };
  String[] bb = { "question bb" };
  String[] cc = { "question cc" };
  String[] dd = { "question dd" };
  
  
  String[][] questions = { aa, bb, cc, dd };
  
  
  String[] e = { "answer to question aa" };
  String[] f = { "answer to question bb" };
  String[] g = { "answer to question cc" };
  String[] h = { "answer to question dd" };
  
  
  String[][] answers = { e, f, g, h };
  
  
  int min = 0;
  int max = 5;
  int random= 0;
  
  
  random = min + (int) (Math.random() * max);
  
  
  questions[random];
  answers[random];