- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$x = '<extData>
<orderData>
<order><orderId>6</orderId><orderTime>2014-10-23T02:53:38</orderTime><item><sku>138</sku><title>Beef Pie</title><quantity>1</quantity><price>8.00</price><amount>8.00</amount></item><item><sku>138</sku><title>Beef Pie</title><quantity>-1</quantity><price>8.00</price><amount>-8.00</amount></item><subtotal>0.00</subtotal><fee>0.00</fee><total>0.00</total><orderStatus>COMP</orderStatus></order><schema_version>2</schema_version>
</orderData>
</extData><price>±';
preg_match('/<extData>(.*)<\/extData>/m',$x, $matches);
var_dump($matches);