title: what is difference between #import and inheritance?
body: <p>in classa.h</p>
  
  <pre><code>#import "ClassB.h"
  @inteface classa : ClassB
  </code></pre>
  
  <p>what is advantage of inheritance and what is advantage of import</p>
  
  <p>please explain</p>
  
  <p>in classa.m  </p>
  
  <pre><code>    #import "ClassB.h"
  </code></pre>
  
  <p>access the member in class file.
  same thing access the member in ClassB</p>
  
  <p>what is different?</p>