What is the main purpose and advantage of using a linked list in programming?

A linked list is a data structure consisting of nodes, where each node contains data and a reference to the next (and sometimes the previous) node. The main purpose of a linked list is to efficiently manage dynamic data with the ability to quickly add and remove elements without the need to shift other elements, as in an array.

Advantages:

• Dynamic size: the list can be easily increased or decreased during runtime.
• Efficient addition/removal: insertion and deletion operations in the middle of the list are performed in O(1) if there is a reference to the desired node.
• No need to allocate a large contiguous block of memory, as in an array.

Example in JavaScript (Node.js):

class Node {
  constructor(value) {
    this.value = value;
    this.next = null;
  }
}

class LinkedList {
  constructor() {
    this.head = null;
  }

  append(value) {
    const newNode = new Node(value);
    if (!this.head) {
      this.head = newNode;
      return;
    }
    let current = this.head;
    while (current.next) {
      current = current.next;
    }
    current.next = newNode;
  }
}