if(!isset) function

TweetyPie

I just want to clarify what the following fucntions as

if (!isset($submit))

this is what i made of it:

//If ‘isset’ is the same then it submits. It basically checks to see if the $submit variable has been initialised. this is in the context of a form submission and is used to test whether or not a form has been submitted. Its checking to see if an input with the name submit has been set.

Is that correct?

if it is

if(isset($submit))

with out the ' ! '. Is that still the same?

seby

$submit will only work on servers where globals is active.
anyhow, here is an example:

if(!isset($submit)) 
{
	// this is where you would display the form or anything else before subitting.
}

if(isset($submit))
{
	// user submitted the form.. do whatever .
}

so your partly correct... hence "is set" .. if you add a ! in front of isset it means the form hasn't been submitted.. you can also do away with two ifs and just use an else {

but i prefer using two ifs.

mcgruff

The ! means "not" ie "is not set".

As mentioned above, a better way is to check:

if(!isset($_POST['submit']))

(assuming the form method is POST - which it should be).

This will work on any server regardless of the register globals on/off setting.

It's also slightly more secure since a hacking attempt would require some form forging rather than query string tampering. That's still perfectly possible, just requires a little bit more effort from the hacker. Any GPC input should always be regarded as suspect and dealt with accordingly.