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Oracle 1z0-830 Exam Overview:
| Certification Vendor: | Oracle |
|---|---|
| Exam Name: | Java SE 21 Developer Professional |
| Exam Number: | 1Z0-830 |
| Certificate Validity Period: | 18 months |
| Exam Price: | $300 USD |
| Exam Duration: | 120 minutes |
| Exam Format: | Multiple Choice, Multiple Select |
| Real Exam Qty: | 50 |
| Related Certifications: | Oracle Certified Professional: Java SE 17 Developer Oracle Certified Professional: Java SE 11 Developer |
| Passing Score: | 68% |
| Available Languages: | English, Japanese, Chinese (Simplified) |
| Recommended Training: | Oracle Java SE 21 Developer Training |
| Exam Registration: | Oracle University Registration Pearson VUE |
| Sample Questions: | Oracle 1z0-830 Sample Questions |
| Exam Way: | Online proctored or onsite at Pearson VUE test centers |
| Pre Condition: | No mandatory prerequisites; recommended 2+ years of Java development experience or equivalent knowledge |
| Official Syllabus URL: | https://education.oracle.com/java-se-21-developer/pexam_1Z0-830 |
Oracle 1z0-830 Exam Syllabus Topics:
| Section | Weight | Objectives |
|---|---|---|
| Topic 1: Using Object-Oriented Concepts | 20% | - Enums, nested classes, local variable type inference - Classes, records, objects, constructors, initializers, methods, fields, encapsulation - Overloading, overriding, Object class methods, immutable objects - Inheritance, abstract classes, sealed classes, interfaces, polymorphism |
| Topic 2: Modules and Packaging | 5% | - Create and use JAR files, modular and non-modular builds - Module system: module-info.java, exports, requires, provides, uses |
| Topic 3: Handling Date, Time, Text, Numeric and Boolean Values | 12% | - Use Date-Time API: LocalDate, LocalTime, LocalDateTime, Period, Duration, Instant, ZonedDateTime - Use primitives and wrapper classes, evaluate expressions and apply type conversions - Manipulate text, text blocks, String, StringBuilder and StringBuffer |
| Topic 4: Controlling Program Flow | 10% | - Loops: for, enhanced for, while, do-while, break, continue, return - Decision constructs: if-else, switch expressions and statements, pattern matching |
| Topic 5: Advanced Features and Annotations | 3% | - Annotations, built-in annotations, custom annotations - Generics, type parameters, wildcards, type erasure |
| Topic 6: Java I/O and Localization | 5% | - Resource bundles, locale, formatting messages, numbers, dates - File I/O, NIO.2, streams, readers/writers, serialization |
| Topic 7: Handling Exceptions | 8% | - Create and use custom exceptions, throw, throws - Exception hierarchy, try-catch-finally, multi-catch, try-with-resources |
| Topic 8: Working with Arrays and Collections | 12% | - Collections Framework: List, Set, Map, Deque, Queue, sorting, searching - Declare, instantiate, initialize, use arrays and multidimensional arrays |
| Topic 9: Concurrency and Multithreading | 10% | - Synchronization, locks, concurrent collections, thread safety - Thread lifecycle, Runnable, Callable, ExecutorService, virtual threads |
| Topic 10: Functional Programming and Streams | 15% | - Lambda expressions, functional interfaces, method references - Optional class, primitive streams - Stream API: create, intermediate/terminal operations, parallel streams, grouping, partitioning |
Oracle Java SE 21 Developer Professional Sample Questions:
Given:
java
String colors = "red\n" +
"green\n" +
"blue\n";
Which text block can replace the above code?
- A. None of the propositions
- B. java
String colors = """
red \
green\
blue \
"""; - C. java
String colors = """
red \s
green\s
blue \s
"""; - D. java
String colors = """
red \t
green\t
blue \t
"""; - E. java
String colors = """
red
green
blue
""";
Correct Answer: E 🗳️
Explanation: Only visible for BraindumpQuiz members. You can sign-up / login (it's free).
Given:
java
Period p = Period.between(
LocalDate.of(2023, Month.MAY, 4),
LocalDate.of(2024, Month.MAY, 4));
System.out.println(p);
Duration d = Duration.between(
LocalDate.of(2023, Month.MAY, 4),
LocalDate.of(2024, Month.MAY, 4));
System.out.println(d);
What is the output?
- A. P1Y
UnsupportedTemporalTypeException - B. P1Y
PT8784H - C. UnsupportedTemporalTypeException
- D. PT8784H
P1Y
Correct Answer: A 🗳️
Explanation: Only visible for BraindumpQuiz members. You can sign-up / login (it's free).
Given:
java
Object myVar = 0;
String print = switch (myVar) {
case int i -> "integer";
case long l -> "long";
case String s -> "string";
default -> "";
};
System.out.println(print);
What is printed?
- A. integer
- B. Compilation fails.
- C. string
- D. It throws an exception at runtime.
- E. nothing
- F. long
Correct Answer: B 🗳️
Explanation: Only visible for BraindumpQuiz members. You can sign-up / login (it's free).
Which of the following isn't a valid option of the jdeps command?
- A. --check-deps
- B. --generate-module-info
- C. --list-deps
- D. --print-module-deps
- E. --list-reduced-deps
- F. --generate-open-module
Correct Answer: A 🗳️
Explanation: Only visible for BraindumpQuiz members. You can sign-up / login (it's free).
Which two of the following aren't the correct ways to create a Stream?
- A. Stream<String> stream = Stream.builder().add("a").build();
- B. Stream stream = Stream.ofNullable("a");
- C. Stream stream = Stream.of("a");
- D. Stream stream = new Stream();
- E. Stream stream = Stream.empty();
- F. Stream stream = Stream.generate(() -> "a");
- G. Stream stream = Stream.of();
Correct Answer: A,D 🗳️
Explanation: Only visible for BraindumpQuiz members. You can sign-up / login (it's free).
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