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

Does MapEntry use the key’s hashCode() for hashing?

1. Yes

2. No

3. Only if the key is a String

4. Only for null keys

The correct answer is: Yes

MapEntry does use the key's hashCode() method for hashing as it is used to determine the index in the hash table where the key-value pair will be stored. Option B is incorrect because if the hash code is not used for hashing, then the key-value pair will be stored in a default index, which can result in slower retrieval time. Option C is incorrect because it implies that only String keys use the hashCode() method, which is not true as any object can override this method. Option D is incorrect because the hashCode() method is used for all keys, including null keys.