PHP: 'or' statement on instruction fail: h

Question

Everyone here should know the 'or' statemens, usually glued to an die() command:

$foo = bar() or die('Error: bar function return false.');

The most of the times we see something like:

mysql_query('SELECT ...') or die('Error in during the query');

However, i cant understand how exactly that 'or' statement works.

I would like to throw a new exception instead of die(), but:

try{
    $foo = bar() or throw new Exception('We have a problem here');

Doesnt work, and neither

$foo = bar() or function(){ throw new Exception('We have a problem here'); }

The only way i found to do that is this horrible thought:

function ThrowMe($mess, $code){
    throw new Exception($mess, $code);
}
try{
    $foo = bar() or ThrowMe('We have a problem in here', 666);
}catch(Exception $e){
    echo $e->getMessage();
}

But there is a way to throw a new exception directly after the 'or' statement?

Or this kind of structure is mandatory (i dont liek the ThrowMe function at all):

try{
    $foo = bar();
    if(!$foo){
        throw new Exception('We have a problem in here');
    }
}catch(Exception $e){
    echo $e->getMessage();
}

Edit: what i want is really to avoid the use of an if() check every potential dangerous operation i do, for example:

#The echo $e->getMessage(); is just an example, in real life this have no sense!
try{
    $foo = bar();
    if(!$foo){
        throw new Exception('Problems with bar()');
    }
    $aa = bb($foo);
    if(!$aa){
        throw new Exception('Problems with bb()');
    }
    //...and so on!
}catch(Exception $e){
    echo $e->getMessage();
}

#But i relly prefer to use something like:

try{
    $foo = bar() or throw new Exception('Problems with bar()');
    $aa = bb($foo) or throw new Exception('Problems with bb()');
    //...and so on!
}catch(Exception $e){
    echo $e->getMessage();
}

#Actually, the only way i figured out is:

try{
    $foo = bar() or throw new ThrowMe('Problems with bar()', 1);
    $aa = bb($foo) or throw new ThrowMe('Problems with bb()', 2);
    //...and so on!
}catch(Exception $e){
    echo $e->getMessage();
}

#But i'll love to thro the exception directly instead of trick it with ThrowMe function.

Answer 1

Why don't bar() and bb() throw the exceptions? In PHP Exceptions bubble up, so there's no need to throw the exception in the function/method where you call bar()/bb(). These exceptions may be thrown by bar()/bb(). In case you want to throw another exception, you can simply do:

function foo() {
    try {
        $bar = bar();
    } catch (BarException) {
        throw new FooException;
    }
}