There’s much more to a new Java release than the well-known JEPs.

To properly address any variable, the Java compiler needs to be able to unambiguously determine the context in which it exists.

What happens if an enum constructor is marked as public, protected, or private?

Does it matter if the division uses integers, floats, or doubles? Yes, it does.

What happens when some classes define private methods—and other classes attempt to access them?

Using a file lock to ensure that only a single instance of an application is running

Null keys? No null keys? Let’s see what the quizmasters say.

Oracle’s Mark Reinhold talks with Java Magazine about the most important features in Java SE 7.

The code is throwing exceptions. What’s the real cause?

A pirate treasure can be found as long as there’s some map or reference. So too with a Java object.

Java contains a rich set of methods for dealing with date and time operations. This quiz tests your knowledge of that functionality.

If a mathematical equation’s arguments aren’t accessible, what happens to the math operation?

Lambdas are essentially expressions that define a class and instantiate an object from that class. Do you know how to use them?

Prepare for a tricky adventure when evaluating expressions that contain arrays.

These three classes are powerful—but they can be tricky when combined.

What happens when you throw a checked exception? There are some tricky special cases.

Java Champions love pattern matching for instanceof, records, Stream.toList(), the vector API, the foreign linker API, and the foreign-memory access API.

There are rules about initializing enums. You need to know them.

You never can tell when the Java garbage collector will pick up the trash.

Be sure to know the difference between identifiers and specifiers.