Mastering Java: The Ultimate Quiz for 'Thinking in Java'

What does the 'synchronized' keyword prevent?

1. Variable mutations

2. Race conditions

3. Syntax errors

4. All of the above

The correct answer is: Race conditions

The 'synchronized' keyword is specifically used in Java to provide mutual exclusion and monitor locking in order to prevent race conditions, which occur when multiple threads are accessing and modifying the same shared resource at the same time. Option A, variable mutations, is not a specific term related to concurrency, but it could be referring to the general concept of preventing unwanted changes to variables. Option C, syntax errors, is not related to concurrency at all. Option D, all of the above, includes incorrect options and is therefore not a viable answer.