title: Multi-line strings in PHP
body: <p>Consider:</p>
  
  <pre><code>$xml = "l";
  $xml = "vv";
  
  echo $xml;
  </code></pre>
  
  <p>This will echo <strong>vv</strong>. Why and how can I do multi-line strings for things like <a href="https://en.wikipedia.org/wiki/SimpleXML">SimpleXML</a>, etc.?</p>