Document：doctype 属性
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Document 接口的 doctype 只读属性表示与当前文档关联的文档类型声明（DTD）的 DocumentType 对象。
值
DocumentType 对象。
示例
js
const doctypeObj = document.doctype;
console.log(`doctypeObj.name: ${doctypeObj.name}`);
console.log(`doctypeObj.internalSubset: ${doctypeObj.internalSubset}`);
console.log(`doctypeObj.publicId: ${doctypeObj.publicId}`);
console.log(`doctypeObj.systemId: ${doctypeObj.systemId}`);
备注
如果当前文档没有关联 DTD，该属性将返回 null。
DOM 第 2 级规范不支持编辑文档类型声明。
规范
| Specification |
|---|
| DOM # ref-for-dom-document-doctype① |