- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$xml = <<<'EOT'
<BANKACCTFROM>
<BANKID>300000100
<ACCTID>6393732
<ACCTTYPE>CHECKING
</BANKACCTFROM>
EOT;
$pattern = '%<BANKACCTFROM>
(?=.*<BANKID>(?P<BANKID>[^<\s]+))
(?=.*<ACCTID>(?P<ACCTID>[^<\s]+))
(?=.*<ACCTTYPE>(?P<ACCTTYPE>[^<\s]+))
%sx';
preg_match($pattern, $xml, $m);
var_dump($m);