title: Convert number to byte in PHP
body: <p>In Java, I can easily cast a number to a byte, for example:</p>
  
  <pre class="lang-java prettyprint-override"><code>System.err.println((byte) 13020);
  </code></pre>
  
  <p>the result will be</p>
  
  <pre><code>-36
  </code></pre>
  
  <p>Now how can I achieve the same in PHP?</p>