Debugging with Die() not always works

Well I found this issue that if you are not aware of may cause you trouble while debugging code.
If you try to print a variable within a method by 'die()-ing' on it , it wont print anything if is not "stringed" eg:

**** THIS WONT PRINT ANYTHING *****
Class protip{
function Eg(){
$now = time();
die($now);
}
}

$class = new protip;
$class->Eg();

**** THIS WILL *****
Class protip{
function Eg(){
$now = time();
die(' '.$now); //I know is not a nice way of doing it ,
// you can also go like (string)
}
}
$class = new protip;
$class->Eg();

Any comments? let me know , happy to discuss