PreparedStatement sends SQL to a database. Let’s see how it works.

This intermediate-level Java SE 11 certification quiz tests your ability to declare modules and enable access between modules, especially when it comes to the java.base module.

This Java certification quiz investigates the meaning of default accessibility and how it influences classes in different packages.

Understanding the checked exception mechanism requires that you understand how to declare a method that throws a checked exception, and how that differs from a method that either does not throw any exceptions or throws only unchecked ones.

See if you know how to use the predicate, consumer, function, and supplier interfaces.

Overloaded methods must be valid, and all ambiguities must be resolved.

Java control statements can be confusing to learn and use correctly.

The objective in this Java SE quiz is to understand how to use conditional operators.

You’re tasked with moving an application to JPMS. What’s the command line?

The consumer interface can be confusing, even for advanced coders.

Predicate interfaces can be complicated, so be careful when working out the results.

Can a lambda return a lambda?

Define and implement functional interfaces that work as expected.

The subtleties of using var in lambda expressions

Using var with two-dimensional arrays requires careful attention.

The subtleties of using enums in a switch statement

The effects of declaring a class final

What fields can you access from default methods in interfaces?

When two object references point to the same StringBuilder instance, how are changes propagated?

Nuances of variable scope in for-loops