1. /*
    2.       树的操作：添加、删除、查找、修改
    3.       树节点数据 - 父子
    4.     */
    6.     class Tree{
    7.       constructor(value) {
    8.         this.root = new TreeNode(value);
    9.       }
    11.       getRoot() {
    12.         return this.root;
    13.       }
    15.       getById(id) {
    16.         function find(node) {
    17.           if(node.id === id) {
    18.             return node;
    19.           } else {
    20.             for(let i = 0; i < node.childNode.length; i++) {
    21.               let res = find(node.childNode[i]);
    22.               if(res) return res;
    23.             }
    24.           }
    25.         }
    27.         return find(this.root)
    28.       }
    29.     }
    31.     class TreeNode{
    32.       constructor(value) {
    33.         this.value = value;
    34.         this.parentNode = null;
    35.         this.childNode = [];
    36.         this.id = undefined;
    37.       }
    38.       // 添加子节点
    39.       appendChild(node) {
    40.         this.childNode.push(node);
    41.         node.parentNode = this;
    42.       }
    44.       // 删掉某个子节点
    45.       removeChild(node) {
    46.         // 先按照最底层的写法实现
    47.         for(let i = 0; i < this.childNode.length; i++){
    48.           if(this.childNode[i] === node) {
    49.             this.childNode.splice(i, 1);
    50.             node.parentNode = undefined;
    51.             return ;
    52.           }
    53.         }
    54.       }
    56.       // 查找节点
    58.     }
    60.     const tree = new Tree('html');
    61.     const root = tree.getRoot();
    62.     const header = new TreeNode('header');
    63.     const body = new TreeNode('body');
    64.     const p = new TreeNode('p');
    65.     p.id = 'p1'
    68.     root.appendChild(header);
    69.     root.appendChild(body);
    70.     body.appendChild(p);
    71.     console.log(tree.getById('p1'));
    72.     console.log(root);

    总结：
    image.png