Exploring Java Collections

What is the primary purpose of the List interface in Java?

• To create a fixed-size array of elements.

• The primary purpose of the List interface is to provide an ordered collection that allows for dynamic resizing and indexed access to elements.

• To provide a collection that only allows unique elements.

• To manage elements in a random order without indexing.

Which class is a common implementation of the List interface?

• HashSet

• ArrayList

• TreeMap

• LinkedList

How does a Set differ from a List in Java?

• A Set does not allow duplicates and does not maintain order, while a List allows duplicates and maintains order.

• A List does not allow duplicates and does not maintain order, while a Set allows duplicates and maintains order.

• A Set is a type of List that can only contain unique elements.

• A Set allows duplicates and maintains order, while a List does not.

What is the main characteristic of a Set in Java?

• A Set can contain null values.

• A Set allows duplicate elements.

• A Set does not allow duplicate elements.

• A Set is ordered and indexed.

Which class implements the Set interface and allows duplicate elements?

• None

• HashSet

• TreeSet

• LinkedHashSet

What is the primary use of the Map interface in Java?

• To perform mathematical calculations.

• To create graphical user interfaces.

• To store key-value pairs.

• To manage database connections.

Which method is used to retrieve a value from a Map using a key?

• fetch

• get

• retrieveValue

• access

What is the difference between HashMap and TreeMap?

• HashMap is ordered and allows null keys; TreeMap is unordered and does not allow nulls.

• HashMap is synchronized; TreeMap is not synchronized.

• HashMap does not allow nulls; TreeMap allows null keys and is unordered.

• HashMap is unordered and allows nulls; TreeMap is ordered and does not allow null keys.

What is the purpose of the Queue interface in Java?

• The purpose of the Queue interface in Java is to provide a data structure that allows for FIFO (First-In-First-Out) access to elements.

• To implement a priority-based access system for elements.

• To allow random access to elements in a collection.

• To provide a data structure for LIFO (Last-In-First-Out) access to elements.

Which class is a common implementation of the Queue interface?

• ArrayList

• LinkedList

• Stack

• PriorityQueue