Java MCQ: What is the main difference between HashMap and Hashtable?
a) HashMap is unsynchronized, Hashtable is synchronized
b) HashMap allows null keys and values, Hashtable does not
c) HashMap is generally faster than Hashtable
d) All of the above
Answer:
d) All of the above
Explanation:
The main differences between HashMap and Hashtable are: HashMap is unsynchronized (not thread-safe), while Hashtable is synchronized (thread-safe); HashMap allows null keys and values, whereas Hashtable does not; and HashMap is generally faster than Hashtable due to the lack of synchronization overhead.
Understanding these differences is crucial for selecting the appropriate data structure based on the requirements of your Java application.
Reference links:
https://www.rameshfadatare.com/learn-java-programming/
https://www.javaguides.net/p/java-tutorial-learn-java-programming.html