boolean problem

[Anon]

Hello Folx,

I have a foreach loop where in each loop I read a line from a database. On success the function returns true ("1" to be specific), on false it returns the DBs errormessage (a english string).
I "&&" this returnvalue $db_retval with a boolean variable $err preset to true.

The sourcecode is like this:

$err = true;
foreach ($arr as $key => $value) {
$db_retval = @$dbh->Read("some dblayer crap");
$err = $err && $db_retval;
echo "--$err--\n"; // debugging
}

When $db_retval is true and I "&&" the values I get what I expect. But now my problem: When $err is true and $db_retval contains a string I get true after "&&"ing.

How can that be? Shouldn't PHP interpret anything except "1" as false?

Thanks in advance,

Dominique

[[deleted]]

PHP interprets one '0' (zero) as false.
everything else (including -1) is true.

your database-read function should return 0 on failure, or 1 on success.
The results or error messages should be returned in other ways, like this:

if (read_from_database("SELECT...", $sErrorMsg)
{

no error, be happy.

}
else
{
echo $sErrorMsg;
};

function read_from_database($sQuery, &$sErrorMsg)
{
if ("execute the query")
{
$sErrorMsg = 'No errors';
return true;
}
else
{
$sErrorMsg = 'Big error';
return false;
};
};

[Anon]

vincent give you the best solution, but if you have to use construction like in description, i think you may use string lenght function into boolean expresion

if you will be interested i will send full expresion by mail.

regards