U0. Dynamic Data Structures

Which of the following is a feature of ArrayList in Java?

• Does not allow duplicate elements.

• Elements are stored in key-value pairs.

• Maintains the order of elements.

• Guarantees unique elements.

What is the primary use case for a HashSet?

• Storing elements in a specific order.

• Allowing duplicate elements.

• Storing unique elements without maintaining order.

• Associating values with keys.

Which method is used to add an element to an ArrayList?

• put()

• add()

• set()

• insert()

What happens when you try to add a duplicate key to a HashMap?

• The program throws a runtime exception.

• The existing value for the key is replaced with the new value.

• The new key-value pair is ignored.

• The program crashes.

Which data structure is most suitable for managing key-value pairs in Java?

• ArrayList

• HashSet

• HashMap

• LinkedList

Considering the code in the image, what will the output be?

• 0

• 1

• 2

• 3

Which method can be used to retrieve the value associated with a key in a HashMap?

• getValue()

• find()

• get()

• lookup()

How can you iterate through all the keys of a HashMap?

• Using keySet() and a for loop.

• Using values() and a for loop.

• Directly iterating on the HashMap object.

• Using the toArray() method.

Which of the following methods can be used to remove an element from a HashSet?

• delete()

• remove()

• pop()

• clear()

Which of the following is a valid consideration when choosing a dynamic data structure?

• Access patterns and frequency of access.

• How often the elements will be printed.

• The number of constructors available in the data structure.

• Compatibility with external frameworks like JDBC.