Java Chapter 11 Questions and Answers with Certified Solutions

Java Chapter 11 Questions and Answers with Certified Solutions What is the main purpose of the Java Collections Framework? To provide a set of reusable data structures and algorithms for managing collections of objects What is the difference between an ArrayList and a LinkedList in Java? An ArrayList is backed by a dynamic array, providing fast random access, while a LinkedList uses a doubly linked list, making insertions and deletions faster Which interface does every collection class in Java implement directly or indirectly? The Collection interface What method is used to add an element to an ArrayList? The add() method What happens when you try to insert a duplicate key into a HashSet? The duplicate key is ignored since HashSet does not allow duplicate values 2 Which collection class maintains elements in the order they were inserted? The LinkedHashSet class What is the default capacity of an ArrayList when it is first created without specifying a size? 10 How does a HashMap handle collisions? By using a technique called chaining, where multiple elements are stored in a bucket using a linked list Which method is used to retrieve a value from a HashMap using a key? The get() method What does the iterator() method in a collection return? An Iterator object that can be used to traverse elements in the collection What is the key difference between HashMap and TreeMap? 3 HashMap does not maintain any order, while TreeMap stores keys in a sorted order Which Java class is best suited for implementing a stack data structure? The Stack class How can you check if a HashSet contains a specific element? Using the contains() method