title: i am getting warning: incompatible Objective-C types assigning 'struct NSString *', expected 'struct NSMutableString *'
body: <p>i am getting  warning: incompatible Objective-C types assigning 'struct NSString *', expected 'struct NSMutableString *'  on this line:-  </p>
  
  <pre><code> Value = [Value stringByAppendingString:str];
  </code></pre>
  
  <p>I declared Value as</p>
  
  <pre><code> NSMutableString* Value;
  </code></pre>
  
  <p>How to rectify this?</p>