title: Find exact same string in multiple strings
body: <p>The following example.</p>
  
  <p>I have an array like this :</p>
  
  <pre><code>Array
  (
      [0] =&gt;  vlakke lasflenzen PN6
      [1] =&gt;  vlakke lasflenzen PN10
      [2] =&gt;  vlakke lasflenzen PN16
      [3] =&gt;  vlakke lasflenzen PN25-40
  )
  </code></pre>
  
  <p>I do not know what part of the strings will be the same. And i dont know if the pattern will stay the same. So i cannot explode() on spaces or something.</p>
  
  <p>What i want to try is to extract the part of the srting that is exactly the same between all four of them but split between spaces.</p>
  
  <p>So for this example I would need to extract 'vlakke lasflenzen' from the four strings based on compasison of them.</p>
  
  <p>Can anyone help me?</p>