在 node.js 中创建二叉树并从控制台获取输入

如何解决在 node.js 中创建二叉树并从控制台获取输入

如何在 node.js 中通过从控制台节点逐个节点获取输入并形成树来创建二叉树？

想要创建这样的东西：

     4
    / \
   6   5
  / \  
 8   2

Enter Root Node: 4
Left Child of 4: 6
Left Child of 6: 8
Left Child of 8: *
Right Child of 6: 2
Right Child of 4: 5
Left Child of 5: *
Right Child of 5: *

const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,output: process.stdout
});



function binaryTree() {
    let root = null;

    function Node(element) {
        this.element = element;
        this.left = null;
        this.right = null;
    }

    function create(question) {
        rl.question(question,(answer) => {
            

            if(answer == "*") {
                return "*";
            }

            if(answer.includes("exit")) {
                answer = answer.split(" ")[0];
                rl.close();
                if(answer == "*") {
                    return "*";
                }
            }

            let newNode = new Node(answer);
            if(root === null) root = newNode;
            newNode.left = create("Left Child of " + answer + ": ");
            newNode.right = create("Right Child of " + answer + ": ");
            
            return newNode;


        
        });
    }

    function preOrder(head) {
        console.log("head: " + head);
        if( head == "*" || head == null ) {
            return;
        }

        console.log(head.element);
        preOrder(head.left);
        preOrder(head.right);
    }

    function getRoot() {
        return root;
    }

    return {  create,preOrder,getRoot };
}

let bTree = binaryTree();
let bTree_root = bTree.getRoot();

bTree.create("Root Value: ");

上面的代码没有按预期工作。我认为这是由于异步和递归造成的。