Types of Research

Which Java package includes the LinkedList class?

• a. java.lang

• b. java.util

• c. java.collections

• d. java.data

Answer explanation

The LinkedList class is part of the java.util package.

Which is an advantage of linked lists over arrays?

• A) Constant-time random access

• B) Static memory allocation

• C) Dynamic resizing

• D) Lower memory usage

Answer explanation

Linked lists grow/shrink dynamically without preallocating memory.

How do you traverse a singly linked list?

• A) Start at the tail and follow "prev" references

• B) Start at the head and follow "next" references

• C) Use binary search

• D) Access elements by index

Answer explanation

Singly linked lists only allow forward traversal starting from the head.

What type of linked list allows traversal in both directions

• a) Singly Linked List

• b) Doubly Linked List

• c) Circular Linked List

LinkedList<String> list = new LinkedList<>();

// Initial elements

list.add("Alice");

list.add("Bob");

list.add("Charlie");

// Situation: You need to perform the following operations:

// 1. Add "David" at the second position.

// 2. Remove "Charlie" from the list.

// 3. Change "Bob" to "Brian".

What is the correct set of operations?

• a. list.add(1, "David");

  list.remove("Charlie");

  list.set(2, "Brian");

• b. list.add(2, "David");

  list.remove(2);

  list.set(1, "Brian");

• c. list.addLast("David");

  list.removeFirst();

  list.set(1, "Brian");

• d. list.add("David");

  list.remove("Charlie");

  list.set(1, "Brian");

How do you determine the length of an array arr in Java?

• a) arr.length()

• b) arr.length

• c) arr.size()

• d) arr.getLength()

Which of the following is the correct way to declare and allocate memory in an integer array in Java?

• a) int arr = new int[5];

• b) int arr[] = new int[5];

• c) int[] arr = new int[5];

• d) Both (b) and (c)

In a singly linked list, each node contains:

• a) Only data

• b) Data and a reference to the next node

• c) Data and references to both next and previous nodes

• d) Only a reference

Which method is used to add an element at the end of a LinkedList in Java?

• a) addFirst()

• b) addLast()

• c) insertEnd()

• d) append()

How do you add an element at a specific index in a LinkedList?

• a) addAt(index, element)

• b) insertAt(index, element)

• c) add(index, element)

• d) push(index, element)