Constructing an array using a size that may be zero can result in the creation of an empty array. If an empty array is accessed without further checks, an ArrayIndexOutOfBoundsException is thrown.

This can happen when a fixed value of zero, or a random value that may be zero, is used as the size directly.

The size used in the array initialization should be verified to be greater than zero before being used. Alternatively, the array access may be placed within a conditional that ensures it is only accessed if the index is less than the array size.

The following program constructs an array with the size specified by some random value:

The first array construction is protected by a condition that checks if the random value is zero or more. However, if the random value is 0 then an empty array is created, and any array access would fail with an ArrayIndexOutOfBoundsException.

The second array construction is protected by a condition that checks if the random value is greater than zero. The array will therefore never be empty, and the following array access will not throw an ArrayIndexOutOfBoundsException.

Java API Specification: ArrayIndexOutOfBoundsException.