Question 56 of 509
Working with Arrays and CollectionsmediumMultiple ChoiceObjective-mapped

Quick Answer

The correct choice is the one using `Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER).thenComparing(Comparator.comparingInt(Employee::getAge).reversed())`. This works because `thenComparing` allows comparator chaining for multi-field sort with reversed order, applying the primary sort by name (case-insensitive ascending) and then chaining a reversed comparator for age to achieve descending order. On the Oracle Certified Professional Java SE 17 Developer 1Z0-829 exam, this tests your understanding of chaining comparators and applying `reversed()` only to the specific field that needs descending order, rather than reversing the entire chain—a common trap where developers mistakenly call `reversed()` on the whole comparator. Remember that `reversed()` flips the comparator it’s called on, so it must be applied to the age comparator alone, not the combined chain. Memory tip: think “primary first, then reverse the secondary” to keep field-level order control.

1Z0-829 Working with Arrays and Collections Practice Question

This 1Z0-829 practice question tests your understanding of working with arrays and collections. 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.

A developer is implementing a custom sort for a list of Employee objects. The Employee class has fields: String name, int age. The list must be sorted first by name (ascending, case-insensitive), then by age (descending). Which Comparator implementation correctly achieves this?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "first"

    Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

Question 1mediummultiple choice
Full question →

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

Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER).thenComparing(Comparator.comparingInt(Employee::getAge).reversed())

Option B is correct because it first sorts by name using a case-insensitive comparator, then chains a reversed comparator for age, ensuring descending order for age while preserving the primary sort by name. The `thenComparing` method correctly applies the reversed age comparator as a secondary sort, which is essential for multi-field sorting where one field requires descending order.

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.

  • Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER).thenComparingInt(Employee::getAge)

    Why it's wrong here

    Sorts by name case-insensitive ascending, then age ascending - age should be descending.

  • Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER).thenComparing(Comparator.comparingInt(Employee::getAge).reversed())

    Why this is correct

    Correctly sorts by name case-insensitive ascending, then age descending.

    Clue confirmation

    The clue word "first" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Comparator.comparingInt(Employee::getAge).reversed().thenComparing(Employee::getName, String.CASE_INSENSITIVE_ORDER)

    Why it's wrong here

    Sorts by age descending first, then name - name should be primary key.

  • Comparator.comparing(Employee::getName).thenComparingInt(Employee::getAge).reversed()

    Why it's wrong here

    Reverses entire comparator, so name descending, age descending - name should be ascending.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often forget to reverse only the secondary comparator (age) and instead apply `reversed()` to the entire chain, which inverts all sort orders, or they mistakenly use `thenComparingInt` without reversal, leading to ascending age order.

Detailed technical explanation

How to think about this question

The `Comparator.comparing` method with a key extractor and a custom comparator (like `String.CASE_INSENSITIVE_ORDER`) allows fine-grained control over sort behavior without modifying the original class. The `thenComparing` method returns a lexicographic comparator that applies the secondary comparator only when the primary comparison yields equality, which is critical for stable multi-field sorting. In real-world scenarios, such as sorting employee lists for HR reports, case-insensitive name sorting prevents 'Alice' and 'alice' from being treated as distinct entries, while descending age ensures most senior employees appear first within the same name group.

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.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related practice questions

Related 1Z0-829 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Practice this exam

Start a free 1Z0-829 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

FAQ

Questions learners often ask

What does this 1Z0-829 question test?

Working with Arrays and Collections — This question tests Working with Arrays and Collections — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER).thenComparing(Comparator.comparingInt(Employee::getAge).reversed()) — Option B is correct because it first sorts by name using a case-insensitive comparator, then chains a reversed comparator for age, ensuring descending order for age while preserving the primary sort by name. The `thenComparing` method correctly applies the reversed age comparator as a secondary sort, which is essential for multi-field sorting where one field requires descending order.

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.

Are there clue words in this question I should notice?

Yes — watch for: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 11, 2026

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

Sign in to join the discussion.

This 1Z0-829 practice question is part of Courseiva's free Oracle certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 1Z0-829 exam.