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Java: Which practice avoids a common mistake with TreeMap and NavigableMap?

Difficulty:

Medium

Questions:

1

Time Limit:

2 minutes

Passing Score:

100%

Question

Which practice avoids a common mistake with TreeMap and NavigableMap?

  1. Ignore the TreeMap and NavigableMap issue and rely on team discipline instead of APIs or contracts.
  2. Silence the TreeMap and NavigableMap problem by using raw types, broad catches, or shared mutable state.
  3. Prefer the version of TreeMap and NavigableMap that makes behavior less predictable as long as the code compiles.
  4. Do not choose TreeMap for ordinary lookup when ordering is irrelevant, because the extra structure adds cost without value.

Hint

Look for the option that protects correctness instead of hiding the problem.

Answer and rationale

Correct answer: D. Do not choose TreeMap for ordinary lookup when ordering is irrelevant, because the extra structure adds cost without value.

Do not choose TreeMap for ordinary lookup when ordering is irrelevant, because the extra structure adds cost without value. This is a common failure mode in real Java code and a frequent interview follow-up.

Track: Java