please explain to me nature of this error showing up when setting static variable
<p>What I wanted to do is to set static $variable to value 'new value', but there an error shows up, saying: </p>

<pre><code>Parse error: syntax error, unexpected '=' in D:\!TC\www\error.php on line 8

class myobj {
  static protected $variable = null;
  static function test() {
    static::variable = 'new value'
  }
}

$obj = new myobj();
$obj-&gt;test();
</code></pre>
