Java supports the creation and manipulation of arrays, as a data structure. A bunch of Java data structures are implemented using arrays to store and expand their data. Thus, arrays are massively used in programming, as they provide a very fast and easy way to store and access pieces of data. Each array consists of a concrete number of elements and thus, it has a fixed size. The index of an array is an integer value that resides in the interval [0, n-1], where n is the size of the matrix. If we request for an index that is either negative, or greater than or equal to the size of the array, an ArrayIndexOutOfBoundsException is thrown. The ArrayIndexOutOfBoundsException is a RuntimeException thrown only at runtime. The Java Compiler does not check for this error during the compilation of a program.