Extract commas from variable
<p>Hey there, I have this variable:</p>

<pre><code>&lt;?php $blog_description = get_bloginfo('description'); ?&gt;

$blog_description ='I am a text, I have commas, and periods. And I want the text without them';
</code></pre>

<p>How can I extract the commas and periods from $blog_description? 
 I want to use it as meta description in my website header.</p>
