title: Convert a series of PHP variables to a JSON object
body: <p>I have a series of PHP variables:</p>
  
  <pre><code>$a = "a";
  $b = "b";
  $c = "c";
  
  and so on...
  </code></pre>
  
  <p>How can I convert all these variables into one single JSON object? Is this possible?</p>