Java MCQ: What is a Linked List in data structure?
Answer:
Explanation:
A Linked List is a fundamental data structure consisting of a sequence of elements, each called a node. Each node in a linked list contains two parts: a data field to store the value and a reference or pointer to the next node in the sequence. Unlike arrays, linked lists do not store elements in contiguous memory locations; instead, they are linked using pointers. This allows for efficient insertion and deletion of elements, especially in the middle of the list.
Linked lists come in various types, including singly linked lists (where each node points to the next node), doubly linked lists (where each node points to both the next and previous nodes), and circular linked lists (where the last node points back to the first node). The key advantage of linked lists is their dynamic nature, allowing them to grow or shrink in size as needed without reallocating or resizing arrays.
For example, consider a simple linked list:
class Node {
int data;
Node next;
Node(int data) {
this.data = data;
this.next = null;
}
}
class LinkedList {
Node head;
public void add(int data) {
Node newNode = new Node(data);
if (head == null) {
head = newNode;
} else {
Node current = head;
while (current.next != null) {
current = current.next;
}
current.next = newNode;
}
}
}
In this example, each node points to the next node, forming a linked sequence. This structure is particularly useful in scenarios where the list size is unknown or frequently changes, such as in dynamic memory allocation, real-time computing, and implementing queues or stacks.