Quiz yourself: Understanding valid annotation declarations

By Simon Roberts Java SE, Quiz

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

Quiz yourself: Securing untrusted code’s access to file systems

By Simon Roberts Java SE

Do you know how to protect your system’s /etc/passwd file?

Quiz yourself: Use primitives such as the % operator

By Simon Roberts Java SE, Quiz

Test your knowledge of Java’s primitive operators.

Quiz yourself: Security threats and malicious code modifications

By Simon Roberts Java SE, Quiz

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

Quiz yourself: Local variables and unary operators

By Simon Roberts Java SE

Test your knowledge of Java—and your debugging skills too.

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

By Simon Roberts Java SE, Quiz

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

By Simon Roberts Java SE, Quiz

Test your knowledge of static fields in Java.

Quiz yourself: Create and extend abstract classes

By Simon Roberts Java SE, Quiz

Test your knowledge of abstract classes and their methods.

Quiz yourself: Read and write objects by using serialization

By Simon Roberts Quiz

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

Quiz yourself: Apply encapsulation principles to a class

By Simon Roberts Java SE, Quiz

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

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

By Simon Roberts Java SE, Quiz

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

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

By Simon Roberts Java SE, Quiz

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

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

By Simon Roberts Java SE, Quiz

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)

By Simon Roberts Java SE, Quiz

Work with lists while avoiding unpleasant UnsupportedOperationException errors.

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

By Simon Roberts Java SE, Quiz

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

Quiz yourself: Describe the modular SDK (intermediate)

By Simon Roberts Java SE, Quiz

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

Quiz yourself: Use the Optional class (advanced)

By Simon Roberts Coding, Java SE, Quiz

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)

By Simon Roberts Coding, Java SE, Quiz

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

Quiz yourself: Declaring and accessing modules (intermediate)

By Simon Roberts Java SE, Quiz

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)

By Simon Roberts Java SE, Quiz

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