Need to add multiple values to a key in a Java HashMap but can't figure out how to do it? Here are three examples of how to solve the multiple values per key problem in Java.

For new Java programmers, the JOptionPane class is a great visual and user-friendly introduction to user input and Swing-based programming. Here's how to get started.

In prior Java 101 articles, I referred to the concepts of redirection, standard input device, and standard output device. To demonstrate inputting data, several examples called System.in.read().