The hasAttributeNS() method returns TRUE if the current element node has the attribute specified by namespace and name, and FALSE otherwise.
The hasAttributeNS() method returns TRUE if the current element node has the attribute specified by namespace and name, and FALSE otherwise.
方法的作用是：如果当前节点包含指定命名空间和名称所对应的属性，则返回true，否则，则返回false。