Using function call in foreach loop
<p>Are there any issues, with regards to efficiency, for using a function call in a foreach loop.  For example:</p>

<pre><code>foreach ($this-&gt;getValues() as $value) {
  //Do something with $value
}
</code></pre>

<p>versus</p>

<pre><code>$values = $this-&gt;getValues();
foreach ($values as $value) {
  //Do something with $value
}
</code></pre>

<p>Essentially, is php clever enough to call $this->getValues() only once in the first example, or does it call it on each iteration.  If it calls it on each iteration, then how does it keep track of which element its currently at,</p>
