How to use parentnode

How to use parentnode: 1. Create a sample html file; 2. Get the node object with the id "child" through the getElementById method; 3. Use the parentNode attribute to get the parent node object of the node; 4. , just output the id of the parent node as "parent".

#To use the parentNode attribute, you first need to obtain a node object. The specified node object can be obtained through methods such as getElementById and getElementsByTagName. Then, you can use the parentNode attribute to get the parent node of the node.

The following is a simple example that demonstrates how to use the parentNode attribute:

nbsp;html>


  <title>parentNode使用方法</title>


  <div>
    <p>这是一个段落。</p>
  </div>
  <script>
    // 获取子节点对象
    var childNode = document.getElementById("child");
    
    // 使用parentNode属性获取父节点对象
    var parentNode = childNode.parentNode;
    
    // 输出父节点的id
    console.log(parentNode.id); // 输出：parent
  </script>

In the above example, we first obtain the node object with the id "child" through the getElementById method. Then, use the parentNode attribute to obtain the parent node object of the node. Finally, by outputting the id of the parent node, we can see that the id of the parent node is "parent".

It should be noted that if the specified node has no parent node (that is, the node is the root node), the parentNode attribute returns null.

The parentNode attribute is very useful in DOM operations and can be used to find and operate the parent node of a node. For example, you can use the parentNode attribute to delete a node:

var childNode = document.getElementById("child");
childNode.parentNode.removeChild(childNode);

The above code will delete the node with the id "child" and all its child nodes.

In summary, the parentNode attribute is an attribute used in JavaScript to obtain the parent node of a specified node. By obtaining the parent node object, we can perform further operations, such as finding sibling nodes, deleting nodes, etc.

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