我是 JavaScript 的新手，正在嘗試學習數據結構和算法。我正在努力理解如何set通過依賴getIndex.這是代碼：class Node{  constructor(val){    this.val = val;    this.next = null  }}class SinglyLinkedList{  constructor(){    this.head = null;    this.tail = null;    this.length = 0;  }  push(val){    let newNode = new Node(val);    if(!this.head){      this.head = newNode      this.tail = this.head    }else{      this.tail.next = newNode;      this.tail = newNode    }    this.length++;    return this;  }  getIndex(index){    if(index > this.length || index < 0) return null;    let counter = 0, current = this.head;    while(counter !== index){      current = current.next;      counter++;    }    return current; // Here we return a value of the node we found  }  set(val, index){    let foundNode = this.getIndex(index);    if(foundNode){      foundNode.val = val;       // We can change the value of the node we founded in getIndex. Then the set works      // I don't understand why we can do this.       // Since what we do in getIndex is just returning a value of the node.       // How does changing that returned node can change the context of the list in term of the purpose of set      return true;    }    return false;  }}let list = new SinglyLinkedList();list.push(88);list.push(33);list.push(11)list.getIndex(1) // Output: Node: {val: 33, next: 11}. Why does changing this returned node can change the context of the whole list?list.set(77,1)   // Output: true. List (new) : 88 -> 77 -> 11基本上，我關心的是getIndex方法，我們返回一個current節點。然后我們在set方法中改變它。但是是否getIndex只返回該節點的值？getIndex那么，為什么我們可以在從(in )更改返回的節點時更改整個列表set？對不起我的愚蠢問題。隨意調整我的知識，特別是class方面。請幫忙！提前致謝