Includes/Variable Scope

nstevens

hello... quick problem that's got me stuck.

I've got some .php function files that i'm including in my form page.
One - sys_info.php defines the arrays that I use all over the site.

ex:

$semesters = array("08" => "Fall", 
		"01" => "Spring", 				                "06" => "Summer");

In another function page - format_functions.php, I want to use this $semesters array.
ex:

function format_dateToSemester($dateArray)
{
	//! look up the month > semester
	foreach($semesters as $month => $sem)
	{
	       if($month == $dateArray["month"])
	           $dateString = $sem;
	}
	//!going for "Spring 2004" format
	$dateString .= " ".$dateArray["year"];

return $dateString;	
}

So, if I'm calling format_dateToSemester($X) on a page that has

require_once('sys_info.php');
include_once('format_functions.php');

at the top, what is going wrong? I don't want to pass the array into the function, and when I put the global keyword before $semesters, everything breaks.

Thanks in advance.

-n

planetsim

can you explain a little further on what the problem is? At the moment all i can tell is your including files that include functions.

nstevens

Hey planetsim,
Thanks for the quick reply.

When I try to run it, I get the error
error occurred in script /_testing/includes/format_functions.php on line 44: Invalid argument supplied for foreach()

and that's the only thing going on on that page...

Thanks. 🙂
-n

planetsim

function format_dateToSemester($dateArray)
{
    //! look up the month > semester
    foreach($semesters as $month => $sem)
    {
           if($month == $dateArray["month"])
               $dateString = $sem;
    }
    //!going for "Spring 2004" format
    $dateString .= " ".$dateArray["year"];

return $dateString;    
}

The function doesnt have any idea where $semesters is coming from infact the reason for the error is that it doesnt exist until its been executed in the foreach loop.

This topic is variable scope etc, so basically a little of what I have learnt over the years this applies for basically every language out there today.

{

}

Most languages this is a block statement or in perl a naked body, however at the end of the day in variable placed in there is localised for that block, if the variable is initiated there you cannot retrieve the result as its in the block, and to the main body of the program doesnt exist, unless of course you declare it before the block statement.

Now this isnt all about variable scope theres a lot more to it but its an example for what I am about to explain.

The function you use has the two braces, this is also a block however unlike the above statement unless you use global (unless this function is used only for one project or isnt going to be modified much i suggest avoid doing so) you cannot have variables that are outside of this block available in the function. However you have one argument you can put the $semesters variable as another argument or make it global for it to work.