Question

下面的代码找不到错误的地方，让我知道是什么问题...我试图构造二进制搜索树，但无法构造。

function BinarySearchTree(){
  var Node = function(key){
    this.key = key;
    this.left = null;
    this.right = null;
  };
  var root = null;
}
//Inserting a Key into a tree

this.insert = function(key){
  var newNode = new Node(key);
  if(root === null){
    root = newNode;
  }else{
    insertNode(root, newNode);
  }
};

var insertNode = function(node, newNode){
  if(newNode.key < node.key){
    if(node.left === null){
      node.left = newNode;
    }else{
      insertNode(node.left, newNode);
    }
  }else{
    if(node.right === null){
      node.right = newNode;
    }else{
      insertNode(node.right, newNode);
    }
  }
};


var tree = BinarySearchTree();
tree.insert(11);

Answer 1

评论者提到了代码的一些问题，因为它们导致了挂断。首先，您在this或constructor函数外部使用prototype，因此this将被评估为引用了全局对象。另外，当您将BinarySearchTree分配给变量tree时，您不是在调用构造函数，因此，如果要使用console.log(tree)，它将返回值undefined。 / p>

然后如何解决您的问题？

首先，您可以在BinarySearchTree（此后称为BST）定义中添加检查，以返回对象的实例，以防万一您忘记了new关键字。

if (!(this instanceof BinarySearchTree)) {
    return new BinarySearchTree();
}

第二，您想通过将Node替换为root和var，将this.Node构造函数和this.root变量绑定到BST对象。现在，您以后可以在要定义的各种prototype函数中访问它们。

第三，如上所述，重构对insert函数的定义如下：

BinarySearchTree.prototype.insert = function(){}

当然，请使用适当的代码填写该函数。对insertNode做同样的事情。

BinarySearchTree.prototype.insertNode = function(){}

我并不是说代码会起作用，但这应该会创建树作为对象所需要的原型继承。

重构

function BinarySearchTree(){
  if (!(this instanceof BinarySearchTree)) {
    return new BinarySearchTree();
  }
  this.Node = function(key){
    this.key = key;
    this.left = null;
    this.right = null;
  };
  this.root = null;
}
//Inserting a Key into a tree

BinarySearchTree.prototype.insert = function(key){
  var newNode = new this.Node(key);
  if(this.root === null){
    this.root = newNode;
  }else{
    this.insertNode(this.root, newNode);
  }
};

BinarySearchTree.prototype.insertNode = function(node, newNode){
  if(newNode.key < node.key){
    if(node.left === null){
      node.left = newNode;
    }else{
      this.insertNode(node.left, newNode);
    }
  }else{
    if(node.right === null){
      node.right = newNode;
    }else{
      this.insertNode(node.right, newNode);
    }
  }
};

var tree = BinarySearchTree();
tree.insert(11);

Answer 2

您需要进行一些更改才能使其正常运行。

使用new扩展“构造函数”功能
使用BinarySearchTree创建function BinarySearchTree(){ this.Node = function(key){ this.key = key; this.left = null; this.right = null; }; this.root = null; } //Inserting a Key into a tree BinarySearchTree.prototype.insert = function(key){ var newNode = new this.Node(key); if(this.root === null){ this.root = newNode; }else{ this.insertNode(this.root, newNode); } }; BinarySearchTree.prototype.insertNode = function(node, newNode){ if(newNode.key < node.key){ if(node.left === null){ node.left = newNode; }else{ this.insertNode(node.left, newNode); } }else{ if(node.right === null){ node.right = newNode; }else{ this.insertNode(node.right, newNode); } } }; var tree = new BinarySearchTree(); tree.insert(11); tree.insert(12); tree.insert(10); console.log(tree.root)的实例

After that try with this code---

<ngx-datatable #myTable
      class="material server-scrolling-table"
      [rows]="rows"
      [columns]="columns"
      [columnMode]="'force'"
      [headerHeight]="headerHeight"
      [rowHeight]="rowHeight"
      [loadingIndicator]="isLoading"
      [selectionType]="'checkbox'"
      [scrollbarV]="true"
      [hidden]="hideTable"
      (scroll)="onScroll($event.offsetY)"
    >
        <ngx-datatable-row-detail [rowHeight]="100" #myDetailRow (toggle)="onDetailToggle($event)">
          <ng-template let-row="row" let-expanded="expanded" ngx-datatable-row-detail-template>
            <div style="padding-left:35px;">
              <div><strong>Address</strong></div>
              <div>{{row.address.city}}</div>
            </div>
          </ng-template>
        </ngx-datatable-row-detail>
        <ngx-datatable-column *ngFor="let col of columns" 
           [name]="col.prop">
        </ngx-datatable-column>
        <ngx-datatable-column [width]="50"
                          [resizeable]="false"
                          [sortable]="false"
                          [draggable]="false"
                          [canAutoResize]="false">
        <ng-template let-row="row" let-expanded="expanded" ngx-datatable-cell-template>
            <a href="javascript:void(0)"
               [class.datatable-icon-right]="!expanded"
               [class.datatable-icon-down]="expanded"
               title="Expand/Collapse Row"
               (click)="toggleExpandRow(row)">Click on this link
            </a>
        </ng-template>
    </ngx-datatable-column>
    </ngx-datatable>

未捕获的TypeError：无法读取属性“插入”

2 个答案: