Isset always true ?

[Rommeo]

Hi

 

i have a login form and a logincheck.php file.

when i enter directly to logincheck.php the function "isset" gives me true which is wrong. I think the way i m using for isset is true

 

$username = $_POST['form_username'];
	$username = str_replace("_", "", $username);
	$username = trim($username);
$usernameset = isset($username);
echo "username = $username Username exist = $usernameset";

and the output is

1

Is there anything that i need to use additionaly with isset ? Is there any other option ?

 

I will be glad if anyone can help.

Thanx in advance.

 

( as far as i know isset gives true (1) when it's set otherwise zero. )

[Psycho]

isset() merely tells you if the variable has been defined, not whether it has a value or not. So, you could set the value to an empty string or a null value and isset() will return true. Try using

 

!empty()

[genericnumber1]

should also note that empty() will return true if the value is 0 (or bool false, but that can't happen from a form), so make sure a valid value is not 0.

[wildteen88]

When using isset never do:

$var  = $_POST['var'];

if(isset($var))
{
   // do something
}

As that will always evaluate to true. You should do this instead:

if(isset($_POST['var']) && !empty($_POST['var']))
{
    $var  = $_POST['var'];
    // do something
}