What is $this->?
<p>What I think I know so far:</p>

<p>so <code>$this-&gt;</code> is to access a function/var outside its own function/var ?</p>

<p>but how does <code>$this-&gt;</code> know if its a function or a variable ?</p>

<p>why we refer to a var like this <code>$this-&gt;data</code> instead of this <code>$this-&gt;$data</code> ?</p>
