Implement a simple singly linked list with `append(val)`, `toArray()`, and `size()` methods.

💡 Hint 1: A linked list consists of nodes, each with a value and a next pointer. 💡 Hint 2: Keep track of the head node and traverse to the end for append. 💡 Hint 3: Create a Node class with value and next. LinkedList has head and a size counter. ✅ Solution: ```javascript class LinkedList { constructor() { this.head = null; this._size = 0; } append(val) { const node = { value: val, next: null }; if (!this.head) { this.head = node; } else { let curr = this.head; while (curr.next) curr = curr.next; curr.next = node; } this._size++; } toArray() { const arr = []; let curr = this.head; while (curr) { arr.push(curr.value); curr = curr.next; } return arr; } size() { return this._size; } } ```