Quiz yourself: Understanding valid annotation declarations

Explore the allowed method return types to see where the code succeeds… or fails.

Quiz yourself: Use primitives such as the % operator

Test your knowledge of Java’s primitive operators.

Quiz yourself: Security threats and malicious code modifications

Here’s what happens when good code meets bad people.

Quiz yourself: Say “hello” to the 1Z0-819 Java SE 11 certification exam

You now need only pass a single exam to become a certified Java SE 11 Developer.

Quiz yourself: Correctly apply the static keyword to methods and fields

Test your knowledge of static fields in Java.

Quiz yourself: Create and extend abstract classes

Test your knowledge of abstract classes and their methods.

Quiz yourself: Read and write objects by using serialization

Test your knowledge of the java.io.Serializable interface.

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: Declare and use List and ArrayList instances (intermediate)

Work with lists while avoiding unpleasant UnsupportedOperationException errors.

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: Refactoring with the core functional interfaces (intermediate)

See if you know how to improve code by refactoring.