title: What is the proper way to set default method parameter in PHP?
body: <p>Let's say you have a method that expects a numerical value as an argument. What's the proper way to set a default value in the event the argument doesn't exist?</p>
  
  <pre><code>public function saveme($myvar = false) {}
  
  public function saveme($myvar = '') {}
  
  public function saveme($myvar = NULL) {}
  
  public function saveme($myvar = 0) {}
  </code></pre>