title: Remove spaces from a string
body: <pre><code>NSString *s = @"0800 444 333";
  </code></pre>
  
  <p>As you can see, this string has 2 white-spaces in the middle.
  My questions is, how do I get rid of them so the string can become: </p>
  
  <pre><code>s = @"0800444333"
  </code></pre>