// NodeType
const unsigned short ELEMENT_NODE = 1; 元素节点
const unsigned short ATTRIBUTE_NODE = 2; 属性节点
const unsigned short TEXT_NODE = 3; 文本节点
const unsigned short CDATA_SECTION_NODE = 4; CDATA 区段
const unsigned short ENTITY_REFERENCE_NODE = 5; 实体引用元素
const unsigned short ENTITY_NODE = 6; 实体
const unsigned short PROCESSING_INSTRUCTION_NODE = 7; 表示处理指令
const unsigned short COMMENT_NODE = 8; 注释节点
const unsigned short DOCUMENT_NODE = 9; 最外层的Root element,包括所有其它节点
const unsigned short DOCUMENT_TYPE_NODE = 10; <!DOCTYPE………..>
const unsigned short DOCUMENT_FRAGMENT_NODE = 11; 文档碎片节点
const unsigned short NOTATION_NODE = 12; DTD 中声明的符号节点
