JavaScript 中有很多内置对象，它们可以直接在 TypeScript 中当做定义好了的类型。

ECMAScript 的内置对象

Boolean、Number、String、RegExp、Date、Error

 // 内置对象
 //ECMAScript 的内置对象
 //**`Boolean`、Number、`String`、`RegExp`、`Date`、`Error`**
 //例子
 //都是大写开头的 都是new一个对象
 const regexp:RegExp = /\w\d\s/  //声明一个正则表达式
 const date:Date = new Date()
 // const time:number = new Date().getDate()
 const error:Error = new Error('错误')
 const b:Boolean = new Boolean(false)
 const n:Number = new Number(true)
 const s:String = new String('对象')
 ​

DOM 和 BOM 的内置对象

Document、HTMLElement、Event、NodeList 等

 //DOM 和 BOM 的内置对象
 //例子 读出index.html 中 id=list的下面的四个li标签
 const list:NodeList = document.querySelectorAll('#list li')
 console.log(list);
 //读取body
 const body:HTMLElement = document.body
 console.log(body);
 //读取单独的div
 const div:HTMLDivElement|null = document.querySelector('div')
 console.log(div);
 <body>
  <div>
      <ul id="list">
          <li>1</li>
          <li>2</li>
          <li>3</li>
          <li>4</li>
      </ul>
  </div>
 </body>
 <script src="./index.js"></script>

效果：image-20230105180224676

注意

 let body: HTMLElement = document.body;
 let allDiv: NodeList = document.querySelectorAll('div');
 //读取div 这种需要类型断言 或者加个判断应为读不到返回null
 let div:HTMLElement = document.querySelector('div') as HTMLDivElement
 document.addEventListener('click', function (e: MouseEvent) {
 ​
 });
 ​
 //dom元素的映射表
 //所有dom元素都在这里了
 interface HTMLElementTagNameMap {
  "a": HTMLAnchorElement;
  "abbr": HTMLElement;
  "address": HTMLElement;
  "applet": HTMLAppletElement;
  "area": HTMLAreaElement;
  "article": HTMLElement;
  "aside": HTMLElement;
  "audio": HTMLAudioElement;
  "b": HTMLElement;
  "base": HTMLBaseElement;
  "bdi": HTMLElement;
  "bdo": HTMLElement;
  "blockquote": HTMLQuoteElement;
  "body": HTMLBodyElement;
  "br": HTMLBRElement;
  "button": HTMLButtonElement;
  "canvas": HTMLCanvasElement;
  "caption": HTMLTableCaptionElement;
  "cite": HTMLElement;
  "code": HTMLElement;
  "col": HTMLTableColElement;
  "colgroup": HTMLTableColElement;
  "data": HTMLDataElement;
  "datalist": HTMLDataListElement;
  "dd": HTMLElement;
  "del": HTMLModElement;
  "details": HTMLDetailsElement;
  "dfn": HTMLElement;
  "dialog": HTMLDialogElement;
  "dir": HTMLDirectoryElement;
  "div": HTMLDivElement;
  "dl": HTMLDListElement;
  "dt": HTMLElement;
  "em": HTMLElement;
  "embed": HTMLEmbedElement;
  "fieldset": HTMLFieldSetElement;
  "figcaption": HTMLElement;
  "figure": HTMLElement;
  "font": HTMLFontElement;
  "footer": HTMLElement;
  "form": HTMLFormElement;
  "frame": HTMLFrameElement;
  "frameset": HTMLFrameSetElement;
  "h1": HTMLHeadingElement;
  "h2": HTMLHeadingElement;
  "h3": HTMLHeadingElement;
  "h4": HTMLHeadingElement;
  "h5": HTMLHeadingElement;
  "h6": HTMLHeadingElement;
  "head": HTMLHeadElement;
  "header": HTMLElement;
  "hgroup": HTMLElement;
  "hr": HTMLHRElement;
  "html": HTMLHtmlElement;
  "i": HTMLElement;
  "iframe": HTMLIFrameElement;
  "img": HTMLImageElement;
  "input": HTMLInputElement;
  "ins": HTMLModElement;
  "kbd": HTMLElement;
  "label": HTMLLabelElement;
  "legend": HTMLLegendElement;
  "li": HTMLLIElement;
  "link": HTMLLinkElement;
  "main": HTMLElement;
  "map": HTMLMapElement;
  "mark": HTMLElement;
  "marquee": HTMLMarqueeElement;
  "menu": HTMLMenuElement;
  "meta": HTMLMetaElement;
  "meter": HTMLMeterElement;
  "nav": HTMLElement;
  "noscript": HTMLElement;
  "object": HTMLObjectElement;
  "ol": HTMLOListElement;
  "optgroup": HTMLOptGroupElement;
  "option": HTMLOptionElement;
  "output": HTMLOutputElement;
  "p": HTMLParagraphElement;
  "param": HTMLParamElement;
  "picture": HTMLPictureElement;
  "pre": HTMLPreElement;
  "progress": HTMLProgressElement;
  "q": HTMLQuoteElement;
  "rp": HTMLElement;
  "rt": HTMLElement;
  "ruby": HTMLElement;
  "s": HTMLElement;
  "samp": HTMLElement;
  "script": HTMLScriptElement;
  "section": HTMLElement;
  "select": HTMLSelectElement;
  "slot": HTMLSlotElement;
  "small": HTMLElement;
  "source": HTMLSourceElement;
  "span": HTMLSpanElement;
  "strong": HTMLElement;
  "style": HTMLStyleElement;
  "sub": HTMLElement;
  "summary": HTMLElement;
  "sup": HTMLElement;
  "table": HTMLTableElement;
  "tbody": HTMLTableSectionElement;
  "td": HTMLTableDataCellElement;
  "template": HTMLTemplateElement;
  "textarea": HTMLTextAreaElement;
  "tfoot": HTMLTableSectionElement;
  "th": HTMLTableHeaderCellElement;
  "thead": HTMLTableSectionElement;
  "time": HTMLTimeElement;
  "title": HTMLTitleElement;
  "tr": HTMLTableRowElement;
  "track": HTMLTrackElement;
  "u": HTMLElement;
  "ul": HTMLUListElement;
  "var": HTMLElement;
  "video": HTMLVideoElement;
  "wbr": HTMLElement;
 }

 //定义 promise类型
 function promise():Promise<number> {
     return new Promise<number>((resolve,rejict)=>{
         resolve(1)
     })
 }
 ​
 promise().then(res=>{
     console.log(res)
 })

结果为： 输出了 1