How to randomize questions without repetition from SQLite? - android

I'm developing a simple quiz in my android studio. I'm using a database but I would like to randomize the questions every time the user clicks on the quiz button. I have created 5 sample questions so far.

Use Collections.shuffle on your List<Question>, then use an Iterator<Question> to pick out the questions as you click a button.
Assuming you implemented both equals and hashcode for your Question class, then a LinkedHashSet will remove the duplicates, so repetition won't happen.
Here is an Activity based on your class that should show these concepts.
public class QuizActivityMarketing extends Activity {
private Iterator<Question> questionIterator;
private TextView txtQuestion;
private RadioButton rda, rdb, rdc, rdd;
private Button butNext;
private Question currentQ;
private int score = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Define your views
txtQuestion = (TextView) findViewById(R.id.textView1);
rda = (RadioButton) findViewById(R.id.radio0);
rdb = (RadioButton) findViewById(R.id.radio1);
rdc = (RadioButton) findViewById(R.id.radio2);
rdd = (RadioButton) findViewById(R.id.radio3);
butNext = (Button) findViewById(R.id.button1);
// Get and randomize the questions
DbHelperMarketing db = new DbHelperMarketing(this);
final List<Question> questions = db.getAllQuestions();
Collections.shuffle(questions);
questionIterator = new LinkedHashSet<Question>(questions).iterator();
// Setup the first question
if (questionIterator.hasNext()) {
currentQ = questionIterator.next();
setQuestionView(currentQ);
}
// Hook up the button-clicking
butNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Check the correct answer
RadioGroup grp = (RadioGroup) findViewById(R.id.radioGroup1);
RadioButton answer = (RadioButton) findViewById(grp.getCheckedRadioButtonId());
Log.d("yourans", currentQ.getANSWER() + " " + answer.getText());
if (currentQ.getANSWER().equals(answer.getText())) {
score++;
Log.d("score", "Your score" + score);
}
// Load the next question, if there are any
if (questionIterator.hasNext()) {
currentQ = questionIterator.next();
setQuestionView(currentQ);
} else { // Done asking questions
setQuestionView(null);
Intent intent = new Intent(QuizActivityMarketing.this, ResultActivity.class);
Bundle b = new Bundle();
b.putInt("score", score); //Your score
intent.putExtras(b); //Put your score to your next Intent
startActivity(intent);
finish();
}
}
});
}
private void setQuestionView(Question currentQuestion) {
if (currentQuestion != null) {
txtQuestion.setText(currentQuestion.getQUESTION());
rda.setText(currentQuestion.getOPTA());
rdb.setText(currentQuestion.getOPTB());
rdc.setText(currentQuestion.getOPTC());
rdd.setText(currentQuestion.getOPTD());
} else {
txtQuestion.setText("");
rda.setText("");
rdb.setText("");
rdc.setText("");
rdd.setText("");
}
}
}

I suggest doing:
Option1: If you don't want duplicate Questions
Use collections, since Sets doesn't allow duplicates and lists can be shuffled
Adapt (if not already) your class Question, so you can used in the Set and so not allowing duplicates...(by this override equals AND hashcode)
populate the Collection, shuffle it, get a random element of it
Option2: If you only want one of the questions at random
this is quite the same,
instead of using a set use a list...
omit step 2 since duplicated questions are no a big deal...
but still populate the Collection, shuffle it, get a random element of it
and there you are :)

Related

Building an android quiz without using unnecessary activities

I am new to Android programming and want to make a simple quiz that has around 50 questions. My problem is that I am unsure of how to do this without creating 50 individual layouts, java classes and activities. I would like each question to be different, and the format of the questions is multiple choice (A, B, C and D). Any helpful suggestions?
Thanks.
It's easy! Just create one acitivty and then update it's data every time user answers the question:
1) Changing TextView with question
2) Changing Buttons with answers
/*updating question
*questions is the list of questions obviously
*answers is the list of lists:) When you take a list from answers
*you get a list with
*4 items - they are the answers for current question
*/
public void updateQuestion() {
mQuestionTextView.setText(questions.get(currentQuestionNum));
mButtonA.setText(answers.get(currentQuestionNum).get(0));
mButtonB.setText(answers.get(currentQuestionNum).get(1));
mButtonC.setText(answers.get(currentQuestionNum).get(2));
mButtonD.setText(answers.get(currentQuestionNum).get(3));
}
EDIT:
public ArrayList<String> getAnswers(int questionsNumber) {
return ArrayList<String> currentQuestionAnswers = answers.get(questionsNumber);
}
At every question, you can do something like this:
TextView textview = (TextView) findViewById(R.id.question);
question.setText(current_question);
And for the multiple choice, if you are using a RadioGroup, you can have 4 textviews that correspond to each option and you can modify the text, depending on the question.
For recognizing which option has been selected, put this inside an onClickListener
radioGroup = (RadioGroup) findViewById(R.id.radio);
btnSend = (Button) findViewById(R.id.btnSend);
btnSend.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// get selected radio button from radioGroup
int selectedId = radioGroup.getCheckedRadioButtonId();
// find the radiobutton by returned id
radioButton = (RadioButton) findViewById(selectedId);
}
});

How to pass the id's of RadioButton/RadioGroup to another screen in Android? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How do I pass data between activities in Android?
Yes,No,Difficult are three RadioButtons and NEXT is a Button. I don't know how to pass the id's of selected radio button of each screen to last screen. In RESULT screen particular value is to displayed in TextView. Here is a code for one screen:
public class MainActivity extends Activity {
RadioGroup rg;
RadioButton rb;
Button b;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
addListenerOnButton();
}
private void addListenerOnButton() {
rg = (RadioGroup) findViewById(R.id.rg_Ques1);
b = (Button) findViewById(R.id.button1_ques1);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int selectedId = rg.getCheckedRadioButtonId();
rb = (RadioButton) findViewById(selectedId);
Intent i = new Intent(MainActivity.this,Ques2.class);
startActivity(i);
Toast.makeText(getApplicationContext(), rb.getText(), 0).show();
}
});
}
You can use intents or you can store the values in preferences and access preferences wherever you need.
My approach will be different here. I will make only one activity for all the questions. I will keep my questions in a list and load new questions on 'next' button press. When last question is displayed change the button text to 'finish' and load new activity on pressing 'finish' with the correct answers' number in a bundle.
In your initial class you can add an extra to the intent:
int selectedId = rg.getCheckedRadioButtonId();
rb = (RadioButton) findViewById(selectedId);
Intent i = new Intent(MainActivity.this,Ques2.class);
i.putExtra("rb_value", rb.isChecked());
startActvity(i);
In your second class you can get the value of the extra that you passed:
this.getIntent().getExtras().getBoolean("rb_value");
If you need the results from Question One for Question Two, this would be the best method. If you do not need the results from Question 1 for Question Two, but you will need them for Results only, it might be best to look into SharedPreference (From memory, some expressions may be incorrect but close):
In your questions activities:
SharedPreferences sharedPreferences = this.getSharedPreferences("my.app.preferences", 0);
SharedPreferences.Editor sharedPreferences_edit = sharedPreferences.edit();
sharedPreferences_edit.putBoolean("question1", true);
sharedPreferences_edit.commit();
In your Results activity:
SharedPreferences sharedPreferences = this.getSharedPreferences("my.app.preferences", 0);
sharedPreferences.getBoolean("question1");
For loading questions like this, loading up new intents is NOT the best solution, as you will end up layering your app... If i were creating something like this, I would make it able to change the question without having to load up a whole new activity, and upon button press, it will just change the question on the screen while storing the response to a variable/sharedPreferences.

How can I change Views in Layout by clicking a button in Android?

I'm taking Questions and Answers in String[].The TextView has questions and RadioButton has corresponding answers. If Start Button is clicked, first set of question and answers is displayed in Linear Layout1. If Next Button is clicked LinearLayout1 is replaced by next set of question with answers and again if Next Buttonis clicked next set of question has to be replaced and vice versa. Help me in writing code for Next Button
Note: Only LinearLayout 1 should be changed when clicking Next Button
code:
TextView tv;
RadioButton rb1, rb2;
Button bStart, bNext;
String question[] = { "Key Lime Pie is upcoming version",
"Android is Middleware", "Which is latest Android version?" };
String answerA[] = { "True", "False" };
String answerB[] = { "True", "False" };
String answerC[] = { "Android 4.2", "Android 5" };
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ques);
tv = (TextView) findViewById(R.id.textView111);
rb1 = (RadioButton) findViewById(R.id.radioButton1);
rb2 = (RadioButton) findViewById(R.id.radioButton2);
bStart = (Button) findViewById(R.id.startExam);
bNext = (Button) findViewById(R.id.bNext);
bStart.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
tv.setText(question[0]);
rb1.setText(answerA[0]);
rb2.setText(answerA[1]);
}
});
bNext.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
tv.setText(question[1]);
rb1.setText(answerB[0]);
rb2.setText(answerB[1]);
}
});
}
This is a logic problem.
Merge all the answers into a multidimensional array.
Keep track of the current question.
Use the tracking variable to get the question title in question.
Use the tracking variable to get the answers in the multidimensional array of answers. This is the first dimension of the array.
You read the answers in that dimension and display them in rb1 and rb2.
By using what you have there you will have problems extending that code. After all, are you really going to create a new variable for each different set of answers? It does not make any sense. A multidimensional array works.
However... although you can improve your arrays structure and use an int to keep track of the current displayed question (and thus increment it to get the next question after pressing the bNext), I suggest you try to create more meaningful objects, like a Question class, with relevant members (title, optionA, optionB, whatever...), especially because it looks like you're using this code to learn how to program a quiz-styled application.
Then you can create various questions and iterate through then.
But is that the issue there? No. The problem is keeping track of questions and answers. Use a multidimensional array with a tracking variable.
// edited: OK, I'm going to suggest something very quick for you:
static String[] questions = new String[] { "Question 1", "Question 2", "Question 3" };
static String[][] answers = new String[][] {
{"Answer 1.a", "Answer 1.b"},
{"Answer 2.a", "Answer 2.b"},
{"Answer 3.a", "Answer 3.b"},
};
int pos = -1;
void showNextAnswer() {
pos++;
tv.setText(questions[pos]);
rb1.setText(answers[pos][0]);
rb2.setText(answers[pos][1]);
}
bStart.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showNextAnswer();
}
});
bNext.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showNextAnswer();
}
});
As you can, both buttons do the same thing, so it's probably better to only use a next button.
Create a single array for answers. And declare tracking variables for questions and answers as:
String answer[] = {"True", "False" , "True", "False",
"Android 4.2", "Android 5" };
int current = 0; // this is your new variable
int ans = 1; // this is initialized to 1, because
// I assumed your first question and answer
// is displayed with the press of start button
Change your next button listener to this
public void onClick(View v) {
current ++;
if(current < question.length){
tv.setText(question[current]);
rb1.setText(answer[ans+=1]);
rb2.setText(answer[ans+=1]);
}
}

How would I set up a scoring system in a quiz app?

I'm trying to set up a quiz of which each answer will add a certain number of points to a total score. At the moment, I'm concerned with radio buttons. I have set up a radiogroup and I wish for whatever Radio button selected to add to the total score. This is only one part of my program just to note.
When I press the button at the bottom of the xml layout file, I want the score associated with the radio button to be added to the total score. Do you understand?
Here's the class file for the actual xml layout file:
Public class QuestionOne extends Results {
RadioButton answer1, answer2, answer3;
Button oneNext;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.one);
RadioButton answer1 = (RadioButton) findViewById(R.id.oneradio1);
RadioButton answer2 = (RadioButton) findViewById(R.id.oneradio2);
RadioButton answer3 = (RadioButton) findViewById(R.id.oneradio3);
Button oneNext = (Button) findViewById(R.id.onenext);
}
}
It extends the Results class and I did this so it inherits the score integer. Here is the score class:
public class Results extends Activity {
private int score;
public int getScore() {
return score;
}
public Results(int score) {
this.score = score;
}
}
I got that structure from googling and its validity is questionable I'm sure but I think I have the basic idea. Can anyone help me out?
Declare a RadioGroup instead of declaring individual RadioButtons.
answerGroup = (RadioGroup) findViewById(R.id.radioGroupAnswer);
You can get the index of the button which was selected in the RadioGroup.
int index = answerGroup.indexOfChild(findViewById(answerGroup.getCheckedRadioButtonId()));
Then you can use this index value and add score to the total score.
switch(index)
{
case 0 : totalScore = totalScore + x; // x is the score of the first answer
break;
case 1 : totalScore = totalScore + y; // y is the score of the second answer
break;
case 2 : totalScore = totalScore + z; // z is the score of the third answer
break;
}

Add dynamic Radiobutton into RadioGroup

public class MCQSample extends Activity implements OnClickListener{
TextView title;
String gotBread;
RadioGroup AnswerRG;
int value ;
int value1;
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.mcqsample);
title = (TextView) findViewById(R.id.abc);
nextP = (Button) findViewById(R.id.nextP);
backP = (Button) findViewById(R.id.backP);
AnswerRG = (RadioGroup) findViewById(R.id.AnswerRG);
Bundle b = getIntent().getExtras();
value = b.getInt("key", 0);
}
}
Hi guys, im doing the Android app and stuck on create the dynamic radio-button. Because i don't know how many button i need (which depend on the value - user input). I read some posts which can add on the Layout but i want to add into the radioGroup. Is there any ways? Thank
Step #1: Create a new RadioButton via its constructor and configure it as you see fit.
Step #2: Call addView() on your RadioGroup to add the RadioButton to it.
Step #3: There is no step #3
try this way to add radiobutton in RadioGroup:
private final int WC = RadioGroup.LayoutParams.WRAP_CONTENT;
RadioGroup.LayoutParams rParams;
AnswerRG = (RadioGroup) findViewById(R.id.AnswerRG);
RadioButton radioButton = new RadioButton(this);
radioButton.setText("Yellow");
radioButton.setId(1001);//set radiobutton id and store it somewhere
rParams = new RadioGroup.LayoutParams(WC, WC);
AnswerRG.addView(radioButton, rParams);

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