Collections · interview question
Which collection in Java should be used to store key-value pairs allowing null values but not null keys?
Multiple choiceEasychapter-4-curatedpremiumcollectionschoosing-the-right-collection
Answer and explanation
Correct answer
D. HashMap
Why
HashMap allows null values but does not allow null keys. TreeMap also allows null values but sorts the keys. Hashtable does not allow null keys or values.
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