Using extract() with hyphens
<p>If for example you had an associative array which looked something like this:</p>

<pre><code>$array = array('first-value' =&gt; 'Hello');
</code></pre>

<p>And you were then to extract it:</p>

<pre><code>extract($array);
</code></pre>

<p>How would you access "first-value" as hyphens cannot be used in variable names? Is the hyphen replaced with another character? </p>

<p>I have tried the following with no luck...</p>

<pre><code>echo ${'first-value'};
echo $first_value;
echo $firstvalue;
</code></pre>

<p>Couldn't even find an mention of this in the Php manual...</p>

<p>Thanks in advance!</p>
