Why am I getting such random results when checking DNS?

Question

The code is as follows:

$domain = "fosajfjdkgdajfhsd.com";
$check1 = checkdnsrr($domain, "MX");
$check2 = checkdnsrr($domain, "A");
$check3 = (checkdnsrr($domain, "MX") || checkdnsrr($domain, "A"));
$check4 = !(checkdnsrr($domain, "MX") || checkdnsrr($domain, "A"));
die("{$check1} - {$check2} - {$check3} - {$check4}");

However when I check the output to see what it's returning, I get this:

 - 1 - 1 - 

The domain obviously wouldn't exist, so I don't understand why checking the A record is returning true and checking the MX result doesn't give me anything at all. I don't understand what's going wrong here.

Answer 1

$ dig fosajfjdkgdajfhsd.com

; <<>> DiG 9.6.0-APPLE-P2 <<>> fosajfjdkgdajfhsd.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39121
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;fosajfjdkgdajfhsd.com.     IN  A

;; ANSWER SECTION:
fosajfjdkgdajfhsd.com.  0   IN  A   208.69.32.132

;; Query time: 121 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)
;; WHEN: Wed Apr  7 00:59:59 2010
;; MSG SIZE  rcvd: 55

EDIT: Check your DNS provider. Nowadays, lots of them will return their own A record so they can put ads in front of you eyes if the domain can't be resolved. Breaks DNS, but pays the bills.

Answer 2

Ok, so after browsing through all of the examples in the PHP.net documentation for checkdnsrr() I figured out that for A records you are still required to append a '.' to the end of the domain in order to check it validly. I figured PHP would automatically do that kind of thing for you, but whatever works. Results are as expected now.