The Node.lookupPrefix() method returns a DOMString containing the prefix for a given namespace URI, if present, and null if not. When multiple prefixes are possible, the result is implementation-dependent.
Due to bug 312019, this method does not work with dynamically assigned namespaces, that is those set with the Node.prefix property.
NodeNode.appendChild()Node.cloneNode()Node.compareDocumentPosition()Node.contains()Node.getUserData()Node.hasChildNodes()Node.insertBefore()Node.isDefaultNamespace()Node.isEqualNode()Node.isSameNode()Node.isSupported()Node.lookupNamespaceURI()Node.lookupPrefix()Node.normalize()Node.removeChild()Node.replaceChild()Node.setUserData()AttrCDATASectionCharacterDataChildNodeCommentCustomEventDOMConfigurationDOMErrorDOMErrorHandlerDOMExceptionDOMImplementationDOMImplementationListDOMImplementationRegistryDOMImplementationSourceDOMLocatorDOMObjectDOMStringDOMTimeStampDOMTokenListDOMUserDataDocumentDocumentFragmentDocumentTypeElementElementTraversalEntityEntityReferenceEventEventTargetHTMLCollectionMutationObserverNodeFilterNodeIteratorNodeListNonDocumentTypeChildNodeProcessingInstructionRangeTextTimeRangesTreeWalkerXMLDocument