The DOMXPath object doesn't create a reference to the document. If you load a new xml using either load, loadXML or loadHTML functions the DOMXPath object will still query and evaluate over the source in the DOMDocument when it was created.新しい DOMXPath オブジェクトを作成します。
documentDOMXPath に関連付けられた DOMDocument。
registerNodeNSThe DOMXPath object doesn't create a reference to the document. If you load a new xml using either load, loadXML or loadHTML functions the DOMXPath object will still query and evaluate over the source in the DOMDocument when it was created.