DOM Nodes and Node Types

Estimated study time: 14 minutes.

Everything in an XML DOM tree — elements, text, attributes, comments — is represented as a node. Different kinds of content are represented by different node types.

Common Node Types

• Element Node (type 1) — represents a tag, like <title>.
• Attribute Node (type 2) — represents an attribute, like id="102".
• Text Node (type 3) — represents the actual text content inside an element.
• Comment Node (type 8) — represents an XML comment.
• Document Node (type 9) — the root object representing the entire document.

Example Breakdown

<course id="DA-101">
  <!-- main course info -->
  <title>Data Analytics</title>
</course>

• course is an element node.
• id="DA-101" is an attribute node on course.
• The comment is a comment node.
• title is an element node containing a single text node: "Data Analytics".

Why This Matters

Knowing node types matters because DOM methods often behave differently, or only apply to, specific node types — for example, only element nodes have attributes, and only text nodes hold raw character data directly.