How to add Java Scanner char support The Java Scanner class provides methods that take String input and convert that String into any Java primitive type you might need, except for one: the char.

Even better, the above methods are doing the same type coercion on the way in and out that we do for any other Java-based method calling. So your integral numerics are presented to Ruby as Fixnums ...

Learn the four types of polymorphism in Java, then start using subtype polymorphism to execute different forms of the same Java method.