title: Extract first n characters from original string while modifying original string -- effectively str_splice()
body: <p>Say we have string like:</p>
  <pre><code>$string = 'ADJKANKNAKLNKALNFKLANFKLNAKLFNKALN';
  </code></pre>
  <p>Say we need to declare a variable containing the first 5 characters (<code>ADJKA</code>) from <code>$string</code> and remove the first 5 characters from original string.</p>
  <pre><code>$first = 'ADJKA';
  $string = 'NKNAKLNKALNFKLANFKLNAKLFNKALN';
  </code></pre>
  <p>Is there any function in PHP which can achieve this without using second function?  I am thinking something similar to the behavior of <code>array_splice()</code>, but with an input string instead of an input array.</p>
  <p>(I know that <code>str_splice()</code> isn't a native php function.)</p>