title: php synatax $b = (6 << 1); clarification
body: <p>I am not clearly understand about the following code snippets. </p>
  
  <pre><code>$a = (5 &lt;&lt; 0);
  $b = (6 &lt;&lt; 1);
  echo $a|$b;
  </code></pre>
  
  <p>From php.net i knew that &lt;&lt; operator use for shift left but not clear how it works and what is the uses of | operator.
  Any explanation is highly appreciated.
  Thank you</p>