title: Ambiguity with str_replace case or replacement order
body: <p>Having strange problem with str_replace.</p>
  
  <p>Here's my code: </p>
  
  <pre><code>function replace_text($text) {
          $array = array(
          ':big' =&gt; 'BIG',
          ':bigs' =&gt; 'BIIIGSS',
          );
  </code></pre>
  
  <p>The problem is when i enter <code>bigs</code> (with s) the code only turn the text to <code>BIGs</code> not <code>BIIIGSS</code>.</p>