The java.util.Arrays class provides similar “deep” methods for performing equals and hashCode functionality on multi-dimensional arrays: Arrays.deepEquals and Arrays.deepHashCode.

Array types in Java are not implicitly contravariant, but they can be explicitly contravariant , just like generic types. I’ll offer some examples later in the article.

0, 3, null, options, options[0]); The array named options defines the three fields to display in the dialog box. The array is then passed as the seventh of eight parameters required by the JOptionPane ...