Is it valid to re-declare or override an instance variable through inheritance?
<p>I have an abstract ParentClass with an <code>protected $instanceVariable</code>. Now there's a <code>ChildClass</code> which has also an <code>private $instanceVariable</code>. It sets that to an initial value, like:</p>

<pre><code>private $instanceVariable = 5;
</code></pre>

<p>So the child class overrides it and changes the visibility to private. The parent class does not assign a value to that instance variable. It's also declared in the parent class because there are methods that access it.</p>

<p>Is this just fine with PHP?</p>
