PHP and "set" variables.
PHP has a simpler version of The Visual BASIC Variable Problem. In PHP, you can query the symbol table to see if a variable is defined or not. Whilst this seems like a good idea, in practice it's not. It is much easier if the language does not distinguish between a variable not in the symbol table versus containing a special value, usually null. PHP unfortunately evaluates expressions involving non-existent variables uniquely compared to a particular value; this the constant checking that variables "exist" or are "set". When I programmed with PHP, it often drove me up the wall.
(Visual BASIC lets variables have several states other than simply existing with a value. These include Empty and Nothing as well as actually not existing.)
Wade.
Is it enough to love
Is it enough to breathe
Somebody rip my heart out
And leave me here to bleed
| |
Is it enough to die
Somebody save my life
I'd rather be Anything but Ordinary
Please
| -- "Anything but Ordinary" by Avril Lavigne. |
