title: Exception propagation in objective c
body: <p>I am new to Objective-c and creating an custom exception. I want to handle an exception(throw in function3()) in functin1() of implementationC. Here is my code:</p>
  
  <pre><code>@implementatin A
   function3()
    {
      if(contion)
      throw [[ApiException alloc] initwithName:@"", reasong:@"" userInfo:nil];
    }
  
  
  @implementatin B
    function2()
     {
     function3();
      }
  
   @implementatin C
   function1()
       {
        function2();
        }
  </code></pre>