- A
Optional.empty().orElseThrow(IllegalStateException::new) throws IllegalStateException
orElseThrow with a Supplier will throw the exception if the Optional is empty.
- B
Optional.of(null) returns an empty Optional
Why wrong: Optional.of(null) throws NullPointerException; use ofNullable for null-safe.
- C
Optional.ofNullable(null) returns an empty Optional
ofNullable returns Empty Optional if argument is null.
- D
Optional.get() on empty Optional returns null
Why wrong: get() throws NoSuchElementException if Optional is empty.
- E
Optional.ifPresent(v -> System.out.println(v)) with empty Optional does nothing
ifPresent only executes the consumer if a value is present.
Question 440 of 519
1Z0-829 Working with Streams and Lambda Expressions Practice Question
This 1Z0-829 practice question tests your understanding of working with streams and lambda expressions. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which THREE of the following are true about the Optional class? (Choose three.)
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Optional.empty().orElseThrow(IllegalStateException::new) throws IllegalStateException
Option A is correct because `Optional.empty().orElseThrow(IllegalStateException::new)` explicitly throws a new `IllegalStateException` when the Optional is empty. The `orElseThrow` method is designed to throw the provided exception supplier's exception if no value is present.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Optional.empty().orElseThrow(IllegalStateException::new) throws IllegalStateException
Why this is correct
orElseThrow with a Supplier will throw the exception if the Optional is empty.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Optional.of(null) returns an empty Optional
Why it's wrong here
Optional.of(null) throws NullPointerException; use ofNullable for null-safe.
- ✓
Optional.ofNullable(null) returns an empty Optional
Why this is correct
ofNullable returns Empty Optional if argument is null.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Optional.get() on empty Optional returns null
Why it's wrong here
get() throws NoSuchElementException if Optional is empty.
- ✓
Optional.ifPresent(v -> System.out.println(v)) with empty Optional does nothing
Why this is correct
ifPresent only executes the consumer if a value is present.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Oracle OCP Java 17 often tests the distinction between `Optional.of()` and `Optional.ofNullable()`, and the fact that `Optional.get()` throws `NoSuchElementException` rather than returning null, to catch candidates who confuse Optional with a simple null wrapper.
Detailed technical explanation
How to think about this question
The `Optional` class is a container object used to represent a value that may or may not be present, avoiding explicit null checks. Under the hood, `Optional.of()` enforces non-null via `Objects.requireNonNull()`, while `Optional.ofNullable()` allows null and returns `Optional.empty()`. The `orElseThrow` method is a modern replacement for `get()` that provides a clear exception type.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 1Z0-829 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this 1Z0-829 question test?
Working with Streams and Lambda Expressions — This question tests Working with Streams and Lambda Expressions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Optional.empty().orElseThrow(IllegalStateException::new) throws IllegalStateException — Option A is correct because `Optional.empty().orElseThrow(IllegalStateException::new)` explicitly throws a new `IllegalStateException` when the Optional is empty. The `orElseThrow` method is designed to throw the provided exception supplier's exception if no value is present.
What should I do if I get this 1Z0-829 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jul 4, 2026
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