Attr.prefix

The Attr.prefix read-only property returns the namespace prefix of the specified attribute, or null if no prefix is specified.

The following logs "x" to the console.

<div x:id="example" onclick="console.log(this.attributes[0].prefix)"/>

This will only work when a namespace-aware parser is used, i.e. when a document is served with an XML MIME type. This will not work for HTML documents.

• Attr.namespaceURI
• Attr.localName
• Element.prefix