Question 258 of 509
Java Basics and SyntaxhardMultiple ChoiceObjective-mapped

Quick Answer

The answer is any value between 1000 and 2000 inclusive. This occurs because `counter++` is a classic example of a non-atomic increment race condition; the operation is actually three separate steps—read the value, increment it, and write it back—and when two threads interleave these steps without synchronization, one thread’s increment can overwrite the other’s, causing lost updates. On the Oracle Java Foundations 1Z0-811 exam, this question tests your understanding of thread safety and the visibility of shared mutable state, often appearing as a trap where students assume the result is always 2000. The key insight is that without atomicity or synchronization, the final count can be as low as 1000 if one thread’s increments are repeatedly overwritten. Memory tip: think of “read-increment-write” as three separate tickets—if two people grab tickets at the same time, one gets lost.

1Z0-811 Java Basics and Syntax Practice Question

This 1Z0-811 practice question tests your understanding of java basics and syntax. 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 class has a static variable counter initialized to 0. Two threads increment counter 1000 times each using counter++. What is a possible final value of counter?

Question 1hardmultiple choice
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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

Any value between 1000 and 2000 inclusive

Option D is correct because `counter++` is not an atomic operation; it consists of three steps: read, increment, and write. When two threads execute this non-atomic operation concurrently without synchronization, interleaving can cause lost updates, resulting in a final value that is less than 2000 but at least 1000 (since each thread increments at least once). The possible final value is any integer between 1000 and 2000 inclusive.

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.

  • 1000

    Why it's wrong here

    Too low; both threads perform increments.

  • 0

    Why it's wrong here

    Impossible because each thread increments counter.

  • 2000

    Why it's wrong here

    Theoretical maximum but not guaranteed due to race condition.

  • Any value between 1000 and 2000 inclusive

    Why this is correct

    Actual range due to race condition.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Oracle often tests the misconception that `counter++` is atomic, leading candidates to incorrectly choose 2000, when in fact the non-atomic nature allows any value between 1000 and 2000 due to lost updates.

Detailed technical explanation

How to think about this question

Under the hood, `counter++` compiles to bytecode instructions like `getstatic`, `iconst_1`, `iadd`, and `putstatic`, which are not atomic on the Java Virtual Machine (JVM). The Java Memory Model (JMM) allows threads to cache variables locally, so without `volatile` or `synchronized`, updates may not be visible across threads immediately. In real-world scenarios, this race condition is a classic concurrency bug that can lead to data corruption in multi-threaded counters, inventory systems, or any shared mutable state.

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 1Z0-811 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.

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FAQ

Questions learners often ask

What does this 1Z0-811 question test?

Java Basics and Syntax — This question tests Java Basics and Syntax — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Any value between 1000 and 2000 inclusive — Option D is correct because `counter++` is not an atomic operation; it consists of three steps: read, increment, and write. When two threads execute this non-atomic operation concurrently without synchronization, interleaving can cause lost updates, resulting in a final value that is less than 2000 but at least 1000 (since each thread increments at least once). The possible final value is any integer between 1000 and 2000 inclusive.

What should I do if I get this 1Z0-811 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: Jun 30, 2026

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This 1Z0-811 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 1Z0-811 exam.