CODEWITHSUNDEEP
javaandroidindexoutofboundsexception
rich
rich

Reputation: 9

What causes this ArrayIndexOutOfBoundsException?

I'm making a sudoku game for Android but I'm having an issue. The game compiles, but once you get to the game screen and press a button the game crashes.

I checked the logcat and these seems to be the errors:

05-04 09:07:41.620: ERROR/AndroidRuntime(325): FATAL EXCEPTION: main
05-04 09:07:41.620: ERROR/AndroidRuntime(325): java.lang.ArrayIndexOutOfBoundsException
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at org.example.fpsudoku.Button.findScreenV(Button.java:59)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at org.example.fpsudoku.Button.onCreate(Button.java:38)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at android.app.Dialog.dispatchOnCreate(Dialog.java:307)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at android.app.Dialog.show(Dialog.java:225)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at org.example.fpsudoku.Game.showButtonOrError(Game.java:181)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at org.example.fpsudoku.SudokuScreen.onTouchEvent(SudokuScreen.java:221)
05-04 09:07:41.620: ERROR/AndroidRuntime(325):     at android.view.View.dispatchTouchEvent(View.java:3766)

and this is the code that seems to be the problem:

    findScreenV();

    for (int element : usesquare)
    {
        if (element != 0)
            buttons[element - 1].setVisibility(View.INVISIBLE);
    }
    setListeners();
}

private void findScreenV()
{
    button = findViewById(R.id.button);
    buttons[1] = findViewById(R.id.button_1);
    buttons[2] = findViewById(R.id.button_2);
    buttons[3] = findViewById(R.id.button_3);
    buttons[4] = findViewById(R.id.button_4);
    buttons[5] = findViewById(R.id.button_5);
    buttons[6] = findViewById(R.id.button_6);
    buttons[7] = findViewById(R.id.button_7);
    buttons[8] = findViewById(R.id.button_8);
    buttons[9] = findViewById(R.id.button_9);

Upvotes: 0

Views: 1546

Answers (3)

Harinder
Harinder

Reputation: 11944

if an array is of length 9 it means you can retrive arr[0] to arr[8],if you try to retrieve arr[9] which is not there you will get an ArrayIndexOutOfBoundsException.

Upvotes: 1

Datta Kunde
Datta Kunde

Reputation: 467

In Java when you create the array, at that time u need to give the fix size of that array. like Button[] buttons = new Button[9] and then create the object of that array, like buttons[0] = findViewById(R.id.button_1); Other wise use the arrayList as best solution.

Upvotes: 0

Andreas Dolk
Andreas Dolk

Reputation: 114767

Just a guess - array indexes are zero based. If you need 9 buttons, you'll do

Button[] buttons = new Button[9];

to create the array and

button = findViewById(R.id.button);
buttons[0] = findViewById(R.id.button_1);
buttons[1] = findViewById(R.id.button_2);
buttons[2] = findViewById(R.id.button_3);
buttons[3] = findViewById(R.id.button_4);
buttons[4] = findViewById(R.id.button_5);
buttons[5] = findViewById(R.id.button_6);
buttons[6] = findViewById(R.id.button_7);
buttons[7] = findViewById(R.id.button_8);
buttons[8] = findViewById(R.id.button_9);

to populate it. Addressing buttons[9] in my example will definitly create an ArrayIndexOutOfBoundsException

Upvotes: 8

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