title: Extract words from string with preg_match_all
body: <p>I'm not good with regex but i want to use it to extract words from a string. </p>
  
  <p><strong>The words i need should have minimum 4 characters and the provided string can be utf8.</strong> </p>
  
  <p>Example string:</p>
  
  <blockquote>
    <p>Sus azahares presentan gruesos pétalos blancos teñidos de rosa o violáceo en la parte externa, con numerosos estambres (20-40).</p>
  </blockquote>
  
  <p>Desired output:</p>
  
  <pre><code>Array(
      [0] =&gt; azahares
      [1] =&gt; presentan
      [2] =&gt; gruesos
      [3] =&gt; pétalos
      [4] =&gt; blancos
      [5] =&gt; teñidos
      [6] =&gt; rosa
      [7] =&gt; violáceo
      [8] =&gt; parte
      [9] =&gt; externa
      [10] =&gt; numerosos
      [11] =&gt; estambres
  )
  </code></pre>