[RESOLVED] Isset function question please

[SquirrelJ]

It’s probably a bit of an easy question but its confusing me and this is the only place were I know people who understand PHP so sorry about the question.

I have the following piece of code

$company = ($_GET['company']);
if (!isset($username) {

Please could someone explain to me exactly what this is doing??? I know the isset function returns true if a variable is set but what does the ! do before the isset function???

Thank You

[Piranha]

The ! reverses the result of whatever is after it. Some examples:

$abc = "abd";
echo isset($abc); // Echos true
echo !isset($abc); // Echos false

echo (1 < 2); // Echos true
echo !(1 < 2); // Echos false

[SquirrelJ]

So if $username as a value which will return a true outcome, in this case it will actual be a false outcome because it has the ! before it??

[themanwhowas]

basically it means if $username isn't set ....

[Piranha]

Exactly. Just play around with it a little to get a better understanding of it.