A common logic pattern that's seen when dealing with GET and POST parameters in PHP is to check whether the array element exists, then set another variable to that or a default. It usually looks something like this...
If you don't develop with notices turned on (WHICH YOU SHOULD!) you probably haven't seen the problem that this code gets around. Simply referring to
$_GET['var'] will produce a notice if it does not exist.
Code littered with the example above does not aid readability. To work around this I define a simple function that I use instead of the above block. I call it
V but it is more commonly known as
Using this function, the above example looks like this...
And you can actually drop the last parameter because the default default is an empty string.
This can be used with any array, whether one of the superglobals or user-defined.