title: Why does boolval(false) return empty in php?
body: <p>I'm a little confused how the php function <code>boolval</code> works. Consider the following</p>
  
  <p><code>&lt;?php echo boolval(true); // prints 1</code></p>
  
  <p>And contrast with</p>
  
  <p><code>&lt;?php echo boolval(false); // prints nothing?</code></p>
  
  <p>Why am I not getting back either true/false? And why is <code>boolval(false)</code> returning nothing?</p>
  
  <p>I ran into this problem while trying to parse <code>$argv</code> for a boolean argument. What's the correct of extracting a bool value from <code>$argv</code> if not with this function?</p>