Element.prefix

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

string = element.prefix

The following logs "x" to the console.

<x:div onclick="console.log(this.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.

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