Set 如何与 JavaScript 中的单链表中的 Get 配合使用？

Question

我是 JavaScript 的新手，正在尝试学习数据结构和算法。

我正在努力理解如何set通过依赖getIndex.

这是代码：

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，我关心的是getIndex方法，我们返回一个current节点。然后我们在set方法中改变它。但是是否getIndex只返回该节点的值？getIndex那么，为什么我们可以在从(in )更改返回的节点时更改整个列表set？

对不起我的愚蠢问题。随意调整我的知识，特别是class方面。请帮忙！提前致谢

Answer 1

因为您没有返回值，所以您返回的是对该值的引用。单链表的整个概念基于引用。作为一个实验，尝试返回一个新节点。return&nbsp;new&nbsp;Node(current.val)它不会执行相同的操作。这个概念在更深层次上称为 a&nbsp;pointer。