converting Gbs / Mbs to bytes
<p>I have a switch case like this</p>

<pre><code>switch($filesize_in_bytes){
    case "10Mb &lt;= $filesize_in_bytes &lt;= 100Mb":
        //do some stuff and break;

    case "1Gb &lt;= $filesize_in_bytes &lt;= 10Gb":
        //do some stuff and break;
}
</code></pre>

<p>As you can see <code>$filesize_in_bytes</code> is in bytes, now how can I convert those values with Mbs and Gbs into bytes? The cases <code>10Mb, 100Mb, 1Gb and so on</code> I cant hardcode them directly to bytes and the values too are different based on user status.</p>

<p>The case are fetched from database:</p>

<pre><code>$rule1[0] = '10Mb';
$rule1[1] = '100Mb';

$rule2[0] = '1Gb';
$rule2[1] = '10Gb';
</code></pre>
