title: Cannot replace £ with &pound from string
body: <p>I have a HTML string containing £ signs, for some reason i'm not able to replace them. I'm assuming this is an encoding issue although i can't work out how. The site is using ISO-8859-1 for its encoding</p>
  
  <pre><code>$str = '&lt;span class="price"&gt;£89.99&lt;/span&gt;';
  var_dump(mb_detect_encoding($str, 'ISO-8859-1', true)); // outputs ISO-8859-1
  
  echo str_replace(array("£","&amp;pound;"),"",$str); // nothing is removed
  
  echo htmlentities($str); // the entire string is converted, including £ to &amp;pound;
  </code></pre>
  
  <p>Any ideas?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>should have pointed out i want to replace the £ with <code>&amp;pound</code>;  - i had temporarily added <code>&amp;pound</code> to the array of items to replace in case it had already been converted</p>