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 ...

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().

Okay, I've got two objects. There's the Hand object, and the Finger object. These are fake. The mappings are correct, I believe, everything works fine usually, I think I'm just misunderstanding ...