title: What is the difference between $a and $$a in php?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/2715654/what-does-mean-in-php">What does $$ mean in PHP?</a>  </p>
  </blockquote>
  
  
  
  <p>I am new to PHP and I don't know what the difference between <code>$a</code> and <code>$$a</code> is.</p>