JS: Node Type
What is Node Type?
Node type is a integer that indicates the type of the node.
There are unusual kind of nodes. For example:
- The first line in a HTML file the “DTD” such as
<!doctype html>. - comments
<!-- abc -->is also a node. - Certain whitespace between tags is also a node. [see DOM: Whitespace Nodes]
normally, you just want to know the Node Name (aka tag name) or Node value (the content of a node.) But because some nodes are Whitespace Nodes or comment or special, you need to check if node type is the right type, then you can query node name or value. (else you'll get error or null.)
get Node Type
node.nodeType-
Return node's type.
The return value is a number. Usually 1 or 3. “1” means it's a HTML/XML element. “3” means its content.
Here is a complete list of possible return values.
| value | meaning |
|---|---|
| 1 | ELEMENT_NODE |
| 2 | ATTRIBUTE_NODE |
| 3 | TEXT_NODE |
| 4 | CDATA_SECTION_NODE |
| 5 | ENTITY_REFERENCE_NODE |
| 6 | ENTITY_NODE |
| 7 | PROCESSING_INSTRUCTION_NODE |
| 8 | COMMENT_NODE |
| 9 | DOCUMENT_NODE |
| 10 | DOCUMENT_TYPE_NODE |
| 11 | DOCUMENT_FRAGMENT_NODE |
| 12 | NOTATION_NODE |
// show the root node “document”'s type, name, value document.nodeType // 9 document.nodeName // "#document" document.nodeValue // null
// root element has 2 child document.childNodes.length // 2 // this is <!doctype html> document.childNodes[0].nodeType // 10 document.childNodes[0].nodeName // "html" document.childNodes[0].nodeValue // null // this is <html> document.childNodes[1].nodeType // 1 document.childNodes[1].nodeName // "HTML" document.childNodes[1].nodeValue // null
// example of a element node // first paragraph element let xx = document.getElementsByTagName("p")[0]; xx.nodeType // 1 xx.nodeName // "P" xx.nodeValue // null
// example of a text node // first paragraph's content let xx = document.getElementsByTagName("p")[0].firstChild; xx.nodeType // 3 xx.nodeName // "#text" xx.nodeValue // a string of p's content
As of 2012-04-29, this works in all major browsers.