Is it important to explicitly declare properties in PHP?
<p>I have followed a tutorial to create a simple blog writing application in PHP and have modified the classes in this tutorial so that they have additional capabilities.  Modifying this very bare bones app has given me a better understanding of how PHP works, however I have run across an interesting situation. </p>

<p>One of the classes in my project has about a half dozen class properties such as <code>public $id, public $author, public $post</code>. These properties are declared at the beginning of this class however I find that if I remove all but one of these properties the app still functions correctly. </p>

<p>Is it wrong to remove a property declaration such as <code>public $datePosted</code> from the beginning of a class if this class still assigns variables to this property like this: `$this->datePosted = $someVariableName;'</p>
