title: Use and Access Global/Extern Variables in Objective C
body: <p>I know this question has been asked a billion times, but my particular question hasn't been answered. So sorry about the repetitiveness.</p>
  
  <p>So I know how to declare and define extern variables (correct me if I'm wrong):</p>
  
  <p>in foo.h file:</p>
  
  <pre><code>extern NSString *foo;
  </code></pre>
  
  <p>in foo.m file:</p>
  
  <pre><code>NSString *foo = @"fooey";
  </code></pre>
  
  <p>But then say I want to access/change the variable in the hoo.m file. How would I do that?</p>