JavaScript gets node type, node name and node value

Node type

In DOM nodes, each node has a different type.

The commonly used DOM node types in W3C specifications are as follows:

Syntax for obtaining node types:
nodeObject.nodeType
Among them, nodeObject is the DOM node (node ​​object). This property returns the node type as a number, for example, 1 for an element node and 2 for an attribute node.

For example, get the node type of the <div> tag with id="demo":

document.getElementById("demo").nodeType;

The return value of this statement is 1.

For example, get the type value of element node and text node: <div id="demo1">Click here to display the node class

<div id="demo1">点击这里显示节点类型</div>
<script type="text/javascript">
    document.getElementById("demo1").onclick=function(){
        var divType=this.nodeType;
        var textType=this.firstChild.nodeType;   //  this 指当前发生事件的HTML元素，这里是<div>标签
        alert(
            "<div>标签的节点类型是："+divType+"\n"+
            "<div>标签内部文本的节点类型是："+textType
        );
    }
</script>

Please see the demo:

Node name

The node name is the name of the DOM node. Different types of nodes correspond to different node names.

Syntax for getting the node name:

    nodeObject.nodeName

Among them, nodeObject is the DOM node (node ​​object).

For example, get the node name of the <div> tag with id="demo":

document.getElementById("demo").nodeName;

The return value of this statement is DIV.

For example, get the element node name, text node name and document node name:

<div id="demo2">点击这里显示节点名称</div>
<script type="text/javascript">
    document.getElementById("demo2").onclick=function(){
        var divName=this.nodeName;
        var textName=this.firstChild.nodeName;   //  this 指当前发生事件的HTML元素，这里是<div>标签
        var documentName=document.nodeName
        alert(
            "<div>标签的节点名称是："+divName+"\n"+
            "<div>标签内部文本的节点名称是："+textName+"\n"+
            "文档节点的节点名称是："+documentName
        );
    }
</script>

Node value

For text nodes, the node value is the text content; for attribute nodes, the node value is the value of the attribute.

Node values ​​are not available for document nodes and element nodes.

Syntax for getting node value:

 nodeObject.nodeValue

Among them, nodeObject is the DOM node (node ​​object).

For example, get the node value of the text node:

<div id="demo3">点击这里显示文本节点的值</div>
<script type="text/javascript">
    document.getElementById("demo3").onclick=function(){
        alert(this.firstChild.nodeValue);   //  this 指当前发生事件的HTML元素，这里是<div>标签
    }
</script>