Spacing of Output in Java. Java programs without a graphical user interface use a computer's command line to interact with the user. It is vital that the program's command line output is properly ...

Both the JDBC Statement and Connection objects implement the Closeable interface, which means we should invoke the close() method on them when they are no longer in use. This is done automatically if ...

Do you need to know how to sort Java objects in a collection, array, or map? Here's how to use the Comparable and Comparator interfaces and avoid ClassCastExceptions.

What is the contract between equals() and hashcode()? Learn how these methods work together when comparing objects in Java.

Java array size and length Here are the most important concepts developers must know when they size Java arrays and deal with a Java array’s length: The theoretical maximum Java array size is ...