在C++

Question

使用私有類時，沒有在此範圍內誤差宣佈我有一類

class myClass 
{ 
    private: 

     std::list <myInnerClass> mylists; 

     class myInnerClass 
     { 
      // Design for this private class 
     } 
} 

我不明白爲什麼行std::list <myInnerClass> mylists給了我以下錯誤：

- Type 'myInnerClass' was not declared in this scope 
    - Type 'myInnerClass' could not be resolved 

我錯在哪裏？

Answer 1

您在使用內部類聲明它

之前修復：

class myInnerClass 
    { 
     // Design for this private class 
    }; 

    std::list <myInnerClass> mylists; 

Answer 2

您使用myInnerClass聲明之前。

這段代碼可以編譯：

class myClass 
{ 
    private: 
     class myInnerClass 
     { 
      // Design for this private class 
     } 
     std::list <myInnerClass> mylists; 
} 

Answer 3

首先必須聲明的內部類，然後你可以用它

您的代碼

class myClass 
{ 
private: 
    std::list <myInnerClass> mylists; 
    class myInnerClass 
    { 
     // Design for this private class 
    } 
} 

正確的代碼：

class myClass 
{ 
    private: 
    class myInnerClass 
     { 
      // Design for this private class 
     } 
      std::list <myInnerClass> mylists; 
    }