It’s not easy to keep up with Java’s frequent feature releases. If you missed sealed classes, text blocks, records, the new string methods, or the Optional class, let’s fix that.

Sealed classes in Java let developers limit the creation and use of subclasses and preserve the class hierarchy. Here is how sealed classes in Java work.

Classes and objects in Java must be initialized before they are used. You’ve previously learned that class fields are initialized to default values when classes are loaded, and that objects are ...