Default php variable

Posted on 2011-02-21
Medium Priority
Last Modified: 2012-06-21
I'm calling an include at the very top of my code:


i've got this line of code in includes/page_top.php:

<?php if ($crumb2=="wirtzer") echo "Active";?>

now, in the code of the page that is calling includes/page_top.php, i'm defining the crumb2 variable: i.e.:

<?php $crumb2="wirtzer";?>

my issue is that i'm getting server errors (not on the php page but in the log files) like this one:

[Sat Feb 05 10:03:06 2011] [client] PHP Notice:  Undefined variable: crumb2 in /home/derm/includes/submenu-forms.php on line 3

i'm guessing this is because includes/page_top.php loads before the rest of the code containing the actual crumb2 variable definition. can i define a default crumb2 variable in includes/page_top.php? so i don't keep getting these errors?

Question by:phillystyle123
LVL 84

Expert Comment

by:Dave Baldwin
ID: 34948060
The definition needs to come before the 'include' or at least before the 'if'.  You can define and re-define it wherever you want.  It just has to be defined when you try to use it like in the 'if' statement.
LVL 111

Accepted Solution

Ray Paseur earned 2000 total points
ID: 34951122
This message is a Notice, not an Error:

[Sat Feb 05 10:03:06 2011] [client] PHP Notice:  Undefined variable: crumb2 in /home/derm/includes/submenu-forms.php on line 3

In the default installation of PHP, Notices are suppressed.  That means that you can use undefined variables as if they were NULL.  However you have error_reporting() set to display the Notices.  

You can handle this two ways.  You can set error_reporting(E_ALL ^ E_NOTICE) or you can test the variables to see if they are set before you try to use them in other expressions.  The second practice is better from the computer science standpoint.

A third way is to deliberately define the variables with a default value, then overwrite the default value with the data from whatever source you choose.
if (isset($crumb2))
    if ($crumb2 == "wirtzer") 
        echo "Active";

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Author Closing Comment

ID: 34975738
thank you!

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