Given: 11. public class Person { 12. private name; 13. public Person(String name) { 14. this.name = name; 15. } 16. public int hashCode() { 17. return 420; 18. } 19. } Which is true?

technology programming languages

  1. The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map

  2. Deleting a Person key from a HashMap will delete all map entries for all keys of type Person

  3. Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate.

  4. The time to find the value from HashMap with a Person key depends on the size of the map.

Show answer
Correct Option: D

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map - This option is incorrect. The time to determine whether a Person object is contained in a HashSet is dependent on the size of the HashSet. In the worst case scenario, if all the elements in the HashSet have the same hash code (as in the given code where the hash code is always 420), the time complexity becomes O(n), where n is the number of elements in the HashSet.

Option B) Deleting a Person key from a HashMap will delete all map entries for all keys of type Person - This option is incorrect. Deleting a Person key from a HashMap will only delete the specific entry associated with that key. It will not delete entries for other keys of type Person.

Option C) Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate - This option is incorrect. HashSet does not allow duplicate entries. When inserting a second Person object into a HashSet, the first Person object will not be removed as a duplicate. The HashSet will simply not allow the second Person object to be added if it is a duplicate of an existing object.

Option D) The time to find the value from HashMap with a Person key depends on the size of the map - This option is correct. In a HashMap, the time to find the value associated with a specific Person key is dependent on the size of the map. The time complexity for finding an element in a HashMap is typically O(1) on average, but in the worst case scenario, it can be O(n), where n is the number of elements in the map.

The correct answer is D. The time to find the value from a HashMap with a Person key depends on the size of the map.

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