title: Pointer Variable (*) and Double Pointer (**) Usage With Classes in Objective C
body: <pre><code>int a=1;
  
  int * b;
  
  b = &amp;a;
  
  int **c=&amp;b;
  </code></pre>
  
  <p>In Objective-C, the Pointer (*) variable is used for primitive data types as well with classes like NSString, NSError etc...  </p>
  
  <pre><code>NSString *str = @"iOS"; // or NSString *str= [[NSString alloc] initWithString : @"iOS"];
  
  NSArray *arr =[[NSArray alloc] init];
  </code></pre>
  
  <p>I have seen in Objective-C (NSError **) what is use of double pointer objects for classes in Objective-C?  </p>