title: If any element in setA is in setB
body: <p>Just a quick question regarding sets in Obj-c. Given two sets:</p>
  
  <pre><code>NSMutableSet* a = [NSMutableSet setWithObjects: 1, 2, 3, nil];
  NSMutableSet* b = [NSMutableSet setWithObjects: 3, 4, 5, nil];
  </code></pre>
  
  <p>is there a quick and easy way to determine if any element in set A is also in set B?</p>
  
  <p>Something like ...</p>
  
  <pre><code>if ([a contains:[b allObjects]])
     // do something
  </code></pre>