title: How to insert a character into a NSString
body: <p>How do I insert a space to a NSString.</p>
  
  <p>I need to add a space at index 5 into:</p>
  
  <pre><code>NString * dir = @"abcdefghijklmno";
  </code></pre>
  
  <p>To get this result:</p>
  
  <pre><code>abcde fghijklmno
  </code></pre>
  
  <p>with:</p>
  
  <pre><code>NSLOG (@"%@", dir);
  </code></pre>