CODEWITHSUNDEEP
javaandroidshuffle
Leonid Gefter
Leonid Gefter

Reputation: 25

How to determine and use a given number of questions from an array? Android Studio

I have a String[] array of 300+ questions. When I start my "Test Activity" it creates a test with the "whole" lenght of the array (300). However, I would like to use only 115 questions (randomly) from that array. Is this possible to do?

This is my loop code, which I assume is the responsible for the quantity of questions used.?

 //This is my FOR Loop

 public void shuffleChapterRandomTest() {
    shuffledPositionChapterRandomTest = new String[chapterRandomTestQuestions.length];
    for (int k = 0; k < shuffledPositionChapterRandomTest.length; k++) {
        shuffledPositionChapterRandomTest[k] = String.valueOf(k);
    }
    Collections.shuffle(Arrays.asList(shuffledPositionChapterRandomTest));
    Log.i("TAG", "shuffle: " + shuffledPositionChapterRandomTest[0] + " " + shuffledPositionChapterRandomTest[1]);
}

Upvotes: 1

Views: 64

Answers (1)

Mark
Mark

Reputation: 9919

You're almost there, but I think all your shuffled array does is hold a String value of an index, rather than the question. It can be simplified if chapterRandomTestQuestions is that array of string questions.

Create a random list of Strings from the array and return the shuffled questions that can be iterated over as necessary :

 public List<String> shuffleChapterRandomTest() {
    final List<String> randomQuestions = Arrays.asList(chapterRandomTestQuestions);
    Collections.shuffle(randomQuestions);
    return randomQuestions.subList(0, 115);
}

This assumes there are greater than 115 items in the list, so a little unsafe (you could return randomQuestions.subList(0, Math.min(chapterRandomTestQuestions.length, 115)) to stop this issue), otherwise it will throw an IndexOutOfBoundsException

Upvotes: 1

Related Questions