Question

I’m a novice programmer. This may be a simple problem but I’ve never seen this before. First of all, let me clarify that I’m not even trying to manipulate the index. Here’s the part of the code that is causing the exception:

    int[] bumpercatcher = new int[4];


//time variable that helps control events
int time = 0;

public void setup()
{
    bumpercatcher[0]=4;
    bumpercatcher[1]=4;
    bumpercatcher[2]=4;
    bumpercatcher[3]=4;

As you can see I’m trying to set them all equal to 4 at the start of the program. This causes the arrayindexoutofbounds exception. If I set them all equal to 0~3 then there is no problem (until I set them to a value greater than 3 later in the program). I don’t understand it.

-it doesn’t matter if I set the array size to 10, I still get the same exception

-it doesn’t matter if I set only one of the values (i.e. at index 1, which is definitely within bounds of the array). same exception

Is there something I’m doing wrong? Thanks.

well, here’ the entire code if you want to take a look(not too long, 1 class, bad programming practies): http://dl.dropbox.com/u/33501308/Pong.java

Here’s the html from which you can see the program from (not much to see. it just freezes instantly.): http://dl.dropbox.com/u/33501308/bin.zip

by the way I’m using eclipse.

I don’t really know what SSCEE is. sorry

Answer 1

Your posted code file includes loops along the lines of

for(int j: bumpercatcher) { 
    if(bumpercatcher[j]>5) 
       ... 
}

This is an issue. This is a different kind of loop than a traditional for loop. It is an extended or enhanced for, also called a foreach. It reads “for each integer j in array bumpercatcher do x.” You are taking your element j (a value) and using it as an index to the array. When your value exceeds the maximum index, you will get an exception.

Write your code with a proper for loop if you want to access by index, or try simply restructuring your logic like

for (int j : bumpercatcher) {
    if (j > 5) // j is the value!
        ...
}