How to use the JOptionPane’s showOptionDialog method Java’s JOptionPane provides a simple way to read input from the user and display information back. The JOptionPane’s list of methods includes many ...

This Java runtime exception happens when the wrong type of object is placed into an array. In the example below, a BigInteger array is created, followed by an attempt to add a Double. The Double does ...

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.

In Java an array is a way of storing multiple items of the same type. In this quick tutorial we introduce you to the very basics.

Covariance and contravariance might seem esoteric, but you'll need these concepts more than ever as the Java language evolves. Get started with type dependency in array types, generic types, and ...

How to Assign Random Numbers to an Array in Java. Java has a "Random" class that lets you generate a random number you use to implement calculations in your Java source code.