What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?

java.lang.ArrayIndexOutOfBoundsException is an exception that is thrown when you try to access an element of an array with an index that is out of bounds. This can happen if you try to access an index that is either negative or greater than or equal to the length of the array.

For example, consider the following code:

int[] arr = {1, 2, 3};

for (int i = 0; i <= arr.length; i++) {
    System.out.println(arr[i]);
}

This will throw an ArrayIndexOutOfBoundsException because the loop will try to access the element at index 3, which is out of bounds for the array.

To prevent this exception, you should make sure that you are only trying to access valid indices of the array. For example, you can use a loop with a condition that checks if the index is within bounds, like this:

for (int i = 0; i < arr.length; i++) {
    System.out.println(arr[i]);
}

Alternatively, you can use a try-catch block to catch the exception and handle it appropriately:

try {
    System.out.println(arr[3]);
} catch (ArrayIndexOutOfBoundsException e) {
    System.out.println("Error: index out of bounds");
}

I hope this helps! Let me know if you have any questions.