Study 1Z0-830 Java 21 OOP and Object Model: key concepts, common traps, and exam decision cues.
This chapter tests whether you can read Java object structure the way the compiler does. Constructor flow, initialization order, records, and nested types create many subtle but highly testable mistakes.
| Lesson | Focus |
|---|---|
| 4.1 Classes and Records | Learn how the exam tests initialization, record semantics, inner-type behavior, and equality rules. |
| If the question is really about… | Go first to… |
|---|---|
| constructors, static fields, instance fields, or initialization order | 4.1 Classes and Records |
| records and immutability | 4.1 Classes and Records |
| nested, inner, local, or anonymous types | 4.1 Classes and Records |