For the record, I read documentation on boolean comparisons in PHP, but I do not understand how my code relates in this context. I thought I had a problem connecting to MySQL, but it turns out everything is fine and I can make queries without issue. So, MySQL is not really that relevant to this post.
I use this to report errors in an object that tried to connect on construction. Note that I tried ==, ===, != and !== only to get the same problem. I even tried casting the argument to bool and boolean.
Comments in below code blocks are relevant.
private function assert($test){ // Tried renaming in case PHP was funny about it.
if ($test === FALSE){ // Tried ==, ===, !== and != and casting $test.
if ($this->use_exception){
throw new mysql_exception();
}else{
die("MySQL ".mysql_errno()." - ".mysql_error());
}
}
}
Connecting is typical.
$this->con = mysql_connect($host, $un, $pw, false, $ssl ? MYSQL_CLIENT_SSL : 0);
// I get 'yay'
echo mysql_ping($this->con) ? "yay" : "nay";
// This disagrees. Tried no cast, and a cast to bool.
$this->assert((boolean)($this->con != FALSE));
mysql_ping() says everything is ok, but assert() stops the presses no matter what.
I tried every operator and cast combination, even renaming the function out of paranoia over a name clash. Why does assert() only see true?
EDIT:
To make my problem clearer, consider the alternative implementation with Eugen's suggested use of is_resource. The problem is that I just have no idea why the below happens.
private function assert($test){
$test = $test ? true : false;
if ($test === FALSE){
echo "$test === false<br />";
}
if ($test == FALSE){
echo "$test == false<br />";
}
if ($test !== FALSE){
echo "$test !== false<br />";
}
if ($test == FALSE){
echo "$test != false<br />";
}
}
Output is out of order and the value changed after one comparison. Since I can make queries, $test must be true. I should not get output at all, but I do for every operator. I also tried it with FALSE replaced by 0.
Bad PHP instance?
1 !== false
=== false
!== false
!= false
