java.lang.ArrayIndexOutOfBoundsException: length=10; index=10

Question

I have started to work on app that has multiple choice questions, but when I try to run my app it says:

java.lang.ArrayIndexOutOfBoundsException: length=10; index=10

I know what it says but I don't understand where is the problem.

here's my code:

TextView tvq;
    InputStream is;
    String[] question = new String[10];
    ImageButton[] buttons = new ImageButton[4];
    int[] check = {-1, -1 ,-1};
    int[] answersid = {R.drawable.israelflag, R.drawable.spainflag, R.drawable.franceflag, R.drawable.greeceflag, R.drawable.egyptflag, R.drawable.unitedstatesflag, R.drawable.brazilflag, R.drawable.japanflag, R.drawable.turkeyflag, R.drawable.iraqflag};
    int i, randombutton, correctanswerid ,a;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_trivia);
        buttons[0] = (ImageButton) findViewById(R.id.im1);
        buttons[0].setOnClickListener(this);
        buttons[1] = (ImageButton) findViewById(R.id.im2);
        buttons[1].setOnClickListener(this);
        buttons[2] = (ImageButton) findViewById(R.id.im3);
        buttons[2].setOnClickListener(this);
        buttons[3] = (ImageButton) findViewById(R.id.im4);
        buttons[3].setOnClickListener(this);
        tvq = (TextView) findViewById(R.id.tvq);

        try {
            setQuestion();
        } catch (IOException e) {
            e.printStackTrace();
        }

        game();


    }



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_trivia, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    public void setQuestion() throws IOException {
        int z = 0;
        String st = "";
        is = this.getResources().openRawResource(R.raw.questions);
        InputStreamReader isr1 = new InputStreamReader(is);
        BufferedReader br1 = new BufferedReader(isr1);

        while ((st = br1.readLine()) != null) {
            question[z] = st;
            z++;
        }
        is.close();

    }

    @Override
    public void onClick(View v) {
        int id = v.getId();



        if (id == R.id.im1) {
            if (R.id.im1 == correctanswerid)
                Toast.makeText(this, "correct", Toast.LENGTH_LONG).show();
            else
                Toast.makeText(this, "incorrect", Toast.LENGTH_LONG).show();
            game();
        }
        if (id == R.id.im2) {
            if (R.id.im2 == correctanswerid)
                Toast.makeText(this, "correct", Toast.LENGTH_LONG).show();
            else
                Toast.makeText(this, "incorrect", Toast.LENGTH_LONG).show();
            game();
        }
        if (id == R.id.im3) {
            if (R.id.im3 == correctanswerid)
                Toast.makeText(this, "correct", Toast.LENGTH_LONG).show();
            else
                Toast.makeText(this, "incorrect", Toast.LENGTH_LONG).show();
            game();
        }
        if (id == R.id.im4) {
            if ( R.id.im4 == correctanswerid)
                Toast.makeText(this, "correct", Toast.LENGTH_LONG).show();
            else
                Toast.makeText(this, "incorrect", Toast.LENGTH_LONG).show();
            game();
        }


    }

    public void game()
    {
        i = (int) (8 * Math.random());
        tvq.setText(question[i]);
        randombutton = (int) (3 * Math.random());
        buttons[randombutton].setImageResource(answersid[i]);
        correctanswerid = buttons[randombutton].getId();

        ImageButton temp = buttons[randombutton];
        buttons[randombutton] = buttons[buttons.length-1];



        for (int s = 0; s < buttons.length - 1; s++) {
            a = (int) (9 * Math.random());

                for (int k = 0; k < check.length ; k++) {
                    if (check[k] == a || a == i ) {
                        a = (int) (9 * Math.random());
                        while (check[k] == i || a == 1)
                            a = (int) (9 * Math.random());
                    }
                }

            check[s] = a;
            buttons[s].setImageResource(answersid[a]);
        }

    }

}

here's my raw's file:

Israel?
Spain?
France?
Greece?
Egypt?
United States?
Brazil?
Japan?
Turkey?
Iraq?

Thanks for help! (sorry for my bad English)

Answer 1

The problem is with the question array.

String[] question = new String[10];

Here your value for z is exceeding 9, the max index of your question array.

while ((st = br1.readLine()) != null) {
        question[z] = st;
        z++;
    }

You need to stop it going past 9. Like this:

while (((st = br1.readLine()) != null) && (z < 10)) {