<ruby id="bdb3f"></ruby>

    <p id="bdb3f"><cite id="bdb3f"></cite></p>

      <p id="bdb3f"><cite id="bdb3f"><th id="bdb3f"></th></cite></p><p id="bdb3f"></p>
        <p id="bdb3f"><cite id="bdb3f"></cite></p>

          <pre id="bdb3f"></pre>
          <pre id="bdb3f"><del id="bdb3f"><thead id="bdb3f"></thead></del></pre>

          <ruby id="bdb3f"><mark id="bdb3f"></mark></ruby><ruby id="bdb3f"></ruby>
          <pre id="bdb3f"><pre id="bdb3f"><mark id="bdb3f"></mark></pre></pre><output id="bdb3f"></output><p id="bdb3f"></p><p id="bdb3f"></p>

          <pre id="bdb3f"><del id="bdb3f"><progress id="bdb3f"></progress></del></pre>

                <ruby id="bdb3f"></ruby>

                企業??AI智能體構建引擎,智能編排和調試,一鍵部署,支持知識庫和私有化部署方案 廣告
                # 類型推論 如果沒有明確的指定類型,那么 TypeScript 會依照類型推論(Type Inference)的規則推斷出一個類型。 ## 什么是類型推論 以下代碼雖然沒有指定類型,但是會在編譯的時候報錯: ```ts let myFavoriteNumber = 'seven'; myFavoriteNumber = 7; // index.ts(2,1): error TS2322: Type 'number' is not assignable to type 'string'. ``` 事實上,它等價于: ```ts let myFavoriteNumber: string = 'seven'; myFavoriteNumber = 7; // index.ts(2,1): error TS2322: Type 'number' is not assignable to type 'string'. ``` TypeScript 會在沒有明確的指定類型的時候推測出一個類型,這就是類型推論。 **如果定義的時候沒有賦值,不管之后有沒有賦值,都會被推斷成 `any` 類型而完全不被類型檢查**: ```ts let myFavoriteNumber; myFavoriteNumber = 'seven'; myFavoriteNumber = 7; ``` ## 參考 - [Type Inference](http://www.typescriptlang.org/docs/handbook/type-inference.html)([中文版](https://zhongsp.gitbooks.io/typescript-handbook/content/doc/handbook/Type%20Inference.html)) --- - [上一章:任意值](any.md) - [下一章:聯合類型](union-types.md)
                  <ruby id="bdb3f"></ruby>

                  <p id="bdb3f"><cite id="bdb3f"></cite></p>

                    <p id="bdb3f"><cite id="bdb3f"><th id="bdb3f"></th></cite></p><p id="bdb3f"></p>
                      <p id="bdb3f"><cite id="bdb3f"></cite></p>

                        <pre id="bdb3f"></pre>
                        <pre id="bdb3f"><del id="bdb3f"><thead id="bdb3f"></thead></del></pre>

                        <ruby id="bdb3f"><mark id="bdb3f"></mark></ruby><ruby id="bdb3f"></ruby>
                        <pre id="bdb3f"><pre id="bdb3f"><mark id="bdb3f"></mark></pre></pre><output id="bdb3f"></output><p id="bdb3f"></p><p id="bdb3f"></p>

                        <pre id="bdb3f"><del id="bdb3f"><progress id="bdb3f"></progress></del></pre>

                              <ruby id="bdb3f"></ruby>

                              哎呀哎呀视频在线观看