Strange issue with PHP's microtime
<p>I'm trying to use php's microtime() to benchmark how long two loops in my code take, to see which one runs faster. Here's my code:</p>

<pre><code>$now = microtime();

//loop1  here

$elapsed = microtime() - $now;
echo "Elapsed: $elapsed &lt;br /&gt;";
</code></pre>

<p>When I run this for one loop, I get the result in negative numbers, something like: </p>

<pre><code>Elapsed: -0.120572 
</code></pre>

<p>This is strange, since <code>microtime()</code> should always be bigger than its value a few microseconds earlier?</p>

<p>For the second loop, the value is always positive:</p>

<pre><code>Elapsed: 0.005483 
</code></pre>

<p>What's going on here?</p>
