Getting a reference error "ReferenceError: insertLevelOrder is not defined" on function defined inside a class

Question

我试图使用 javaScript 实现一个完整的二叉树，但我得到了 ReferenceError 的错误：insertLevelOrder is not defined 这里是我的代码：


// given array in level order fashion 
class Node {
    constructor(data, left = null, right = null) {
        this.data = data;
        this.left = left;
        this.right = right;
    }
};

class Tree {
    constructor() {
        this.root = null;
    }

    // Function to insert nodes in level order 
    insertLevelOrder(arr, root, i) 
    { 
        // Base case for recursion 
        if (i < arr.length) { 
            var temp = new Node(arr[i]); 
            root = temp; 

            // insert left child 
            root.left = insertLevelOrder(arr, root.left, 2 * i + 1); 

            // insert right child 
            root.right = insertLevelOrder(arr, root.right, 2 * i + 2); 
        } 
        return root; 
    } 

    // Function to print tree nodes in InOrder fashion 
    inOrder(root) 
    { 
        if (root != null) { 
            inOrder(root.left); 
            console.log(root.data + " "); 
            inOrder(root.right); 
        } 
    } 

} 

var tree = new Tree();
var arr = new Array(1, 2, 3, 4, 5, 6, 6, 6, 6 );
tree.root = tree.insertLevelOrder(arr, tree.root, 0);

我在最后添加了一些代码来测试算法我不确定哪里错了

Answer 1

由于您试图在自身内部递归调用 insertLevelOrder，因此您应该将其作为当前实例的方法调用（通过 this.insertLevelOrder）：

root.left = this.insertLevelOrder(arr, root.left, 2 * i + 1); 
root.right = this.insertLevelOrder(arr, root.right, 2 * i + 2);

Answer 2

在 class 中你必须像 this.insertLevelOrder(...

一样使用 this

我已经删除了您在代码中的注释，并在您必须添加的地方添加了注释 this.

class Node {
    constructor(data, left = null, right = null) {
        this.data = data;
        this.left = left;
        this.right = right;
    }
};

class Tree {
    constructor() {
        this.root = null;
    }

    insertLevelOrder(arr, root, i) 
    { 
        if (i < arr.length) { 
            var temp = new Node(arr[i]); 
            root = temp; 

            // you need to add this.
            root.left = this.insertLevelOrder(arr, root.left, 2 * i + 1); 

            // you need to add this.
            root.right = this.insertLevelOrder(arr, root.right, 2 * i + 2); 
        } 
        return root; 
    } 

    inOrder(root) 
    { 
        if (root != null) { 
            this.inOrder(root.left); // you need to add this.
            console.log(root.data + " "); 
            this.inOrder(root.right); // you need to add this.
        } 
    } 

} 

var tree = new Tree();
var arr = new Array(1, 2, 3, 4, 5, 6, 6, 6, 6 );
tree.root = tree.insertLevelOrder(arr, tree.root, 0);

Getting a reference error "ReferenceError: insertLevelOrder is not defined" on function defined inside a class

Getting a reference error "ReferenceError: insertLevelOrder is not defined" on function defined inside a class

javascript

algorithm

binary-tree