What is a ArrayIndexOutOfBoundsException?

java.lang.ArrayIndexOutOfBoundsException is a runtime exception in Java. occurs while processing an array and asking for a position that does not exist within the size of the array.

Since the ArrayIndexOutOfBoundsException is a runtime exception, it doesn’t need to be caught and handled explicitly in application code.

Example of a ArrayIndexOutOfBoundsException

In this example we are trying to access an element at index 5 of the animals array, which has only 2 elements. In this case java.lang.ArrayIndexOutOfBoundsException will be thrown.

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public class ArrayIndexOutOfBoundsExample {

  public void processArray() {

    List animals = new ArrayList<>();

    names.add("cat");

    names.add("dog");



    return animals.get(5);

  }

}

How to Avoid getting ArrayIndexOutOfBoundsException

The ArrayIndexOutOfBoundsException can be avoided using checks and preventive techniques like the following:

1. Always remember that the array is a zero-based index, the first element is at the 0th index and the last element is at length - 1 index.

2. Pay special attention to the start and end conditions of the loop.