Quiz yourself: Apply encapsulation principles to a class

Test your knowledge of a key object-oriented programming concept.

Quiz yourself: Use the Files class to copy or move files and directories

Test your knowledge of the java.nio.file.Files class.

Quiz yourself: Create worker threads using Runnable and Callable (advanced)

Test your knowledge of what happens when you use the ExecutorService.

Quiz yourself: Define the structure of a Java class (intermediate)

Test your knowledge of Java classes, such as their valid names, the use of variables inside a method, and the number of import statements.

Quiz yourself: Search stream data using the findFirst, findAny, and anyMatch methods (advanced)

Streams are complicated. With the right approach, they can be very efficient too.

Quiz yourself: Describe the modular SDK (intermediate)

Know which command-line utilities are mandatory for distributing applications with a custom JRE.

Quiz yourself: Use the Optional class (advanced)

Do you know how to use Optional? Find out in the latest by Simon and Mikalai.

Quiz yourself: Use PreparedStatement to perform database CRUD operations (intermediate)

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

Quiz yourself: Declaring and accessing modules (intermediate)

This intermediate-level Java SE 11 certification quiz tests your ability to declare modules and enable access between modules.

Quiz yourself: Applying access modifiers to Java classes (intermediate)

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

Quiz yourself: Methods that throw an exception (intermediate)

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.

Quiz yourself: Using core functional interfaces (intermediate)

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

Quiz Yourself: Creating and Invoking Overloaded Methods (Intermediate)

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

Quiz Yourself: Using Switch and Case Statements (Intermediate)

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

Quiz Yourself: Use Java operators (Intermediate)

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

Quiz Yourself: Migrating to the Java Platform Module System (Advanced)

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

Quiz Yourself: Using Core Functional Interfaces: Consumer (Advanced)

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

Quiz Yourself: Using Core Functional Interfaces: Predicate (Advanced)

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

Quiz Yourself: Lambda Types (Advanced)

Can a lambda return a lambda?

Quiz Yourself: Two-Dimensional Arrays (Intermediate)

Using var with two-dimensional arrays requires careful attention.