title: How to define const int in .h file properly?
body: <p>In a project, I need to define a const int, I define it in a header as:</p>
  
  <pre><code> extern const int a;
  </code></pre>
  
  <p>And I include that header many times. Then in only one source file, I put:</p>
  
  <pre><code>const int a=10;
  </code></pre>
  
  <p>However when I need to use a in an array bound; i.e.:</p>
  
  <pre><code>int anarray[a];
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>"array bound is not an integer constant"
  </code></pre>
  
  <p>error. Why?</p>