title: How files will be loaded in Visual Studio C++ when built
body: <p>I have three files.</p>
  
  <pre><code>Wood.cpp
  Brick.cpp
  Wall.cpp
  </code></pre>
  
  <p>And my <code>main()</code> function is in Brick.cpp:</p>
  
  <p>Now, when I run the project, it throws error that the <code>className</code> (which is in Wall.cpp) is undefined. What should I do?</p>
  
  <p>I think the <code>main()</code> function is run before the delaration of Wall.cpp file. </p>