Java: What deeper point about StringBuilder vs StringBuffer should a senior Java developer mention?

Difficulty:

Hard

Questions:

1

Time Limit:

2 minutes

Passing Score:

100%

Question

What deeper point about StringBuilder vs StringBuffer should a senior Java developer mention?

  1. At senior level, the right answer is that StringBuilder vs StringBuffer exists mostly for historical syntax reasons.
  2. At senior level, the JVM removes the tradeoffs around StringBuilder vs StringBuffer, so design choices barely matter.
  3. A thread-safe builder does not automatically make the whole string-construction workflow thread-safe, because surrounding shared state still matters.
  4. At senior level, any approach to StringBuilder vs StringBuffer is equally correct if it compiles and passes a small test.

Hint

Look beyond syntax and explain the runtime, API, or design consequence.

Answer and rationale

Correct answer: C. A thread-safe builder does not automatically make the whole string-construction workflow thread-safe, because surrounding shared state still matters.

A thread-safe builder does not automatically make the whole string-construction workflow thread-safe, because surrounding shared state still matters. This is the kind of tradeoff-aware answer senior interviews usually expect.

Track: Java