title: iOS - how do I create a "utility" class that all my controllers can call
body: <p>I am new to iOS and obective-c so I am not too sure how to best accomplish this seemingly simple task.</p>
  
  <p>What I want is to make a class that looks like this in pseudocode:</p>
  
  <pre><code>class UtilityClass
  {
      // Have a method that I can pass parameters to 
      String doCalculation ( String art1 , String arg2 )
      {
          return arg1 + arg2;
      }
  }
  </code></pre>
  
  <p>My uncertainty is:</p>
  
  <p>1) xCode seems to be inclined to lay out my file structure in a relatively flat way. So should I make a utils directory and have this file be under utils/fileName ? Usually I am kind of used to having at least some src directory, but so far I have not been prompted by anything to create one.
  2) How do I import and call this class/function from my controllers?</p>
  
  <p>Thanks,
  Alex</p>