PHP Notice: Undefined index:

[davidz]

My question if more of a "good practice" type of thing.  Let say I have a session variable $_SESSION['username'].  And I want to display some text based upon the fact that this variable exists.  So if I do this:

<?php 
if ($_SESSION['username'] == 'bob@domain.com') {
     echo "Hello World";
}
?>

 

When I do this, I get

PHP Notice:  Undefined index:  username

in my log messages.  Now granted this is just a notice and not an error.

 

So, my question is, is there anything wrong with this?  Or is it really necessary to do checks like isset()??

 

Thanks,

David

[Jessica]

use isset(). Not checking is poor programming practice.

[davidz]

Ok, so is there a difference (following good programming practice) in either one of these?

<?php
if (isset($_SESSION['username']) == True){
     echo "Yes it was set"
}
?>

<?php
if (isset($_SESSION['username'])){
     echo "Yes it was set"
}
?>

 

Or these:

<?php
if (isset($_SESSION['username']) == False){
     echo "No it was not set"
}
?>

<?php
if (!isset($_SESSION['username'])){
     echo "No it was not set"
}
?>

 

Thanks,

David

 

[Jessica]

It depends on what you're trying to do.The first one in each set is a bit more clear, but it doesn't really matter.