[Resolved] functions & global vars

bike5

Ok I have page one and page two,
Page one has a functions thats calls a function on page two. Page two creates a global array and I want to use it on page one. When I do this, page one can't find the array.

I even did a if(isset($name)) and it said it wassn't set. On page two I printed out the array in the function, so it tells me that the function was called by page 1 and the global var array does exist and have values, but on page one trying to access the variable doesn't work. Any thoughts?

Also, returning an array is not an option because the global array changes in contents and size depending on a value sent to the function, thats why I need the global var and can't use returning an array.

swr

How are you trying to access the global? The usual way, inside a function, is to declare the variable global:

function foo() {
global $myglobalarray;
print_r($myglobalarray);
}

or the $GLOBALS array:

function foo() {
print_r($GLOBALS['myglobalarray']);
}

You mention "page1" and "page2". If you mean seperate files that are accessed by [man]include[/man] or [man]require[/man] to generate a single page, then the above is all you need. However, if you want to pass variables as the user clicks through your site, you need to store those variables in a session. See the [man]session_start[/man] manual page for an example.

bike5

Page 2:

function GetBikeInfo($table_names)
	{
		require("include/bike_cnt.php");
		require("include/session.php");
		$Query = "SELECT " . $table_names . " FROM $TableName_b WHERE bike_name='$user'";
		$Result = mysql_db_query($DBName, $Query, $Link) or die(mysql_error()); 
		global $col_b;
		$col_b = mysql_fetch_array ($Result);
	}

Page 1:

function CallBike()
{
require("PAGE2");
GetBikeInfo("*");
echo $col_b;

When I echo the statement I should get the word "Array" back but I get nothing because it says $col_b is not set.

I use page 2 GetBikeInfo all the time on other pages but never through another function, and it only has not worked now that I am calling it from antoher function. This might matter too, I call CallBike on page one from within page1 too but I don't think that should matter any difference.

swr

In CallBike, you need to declare $col_b global, just like you do in GetBikeInfo. Or use $GLOBALS['col_b']. Either one fix your problem.

You can only access global variables without doing that when you are in a global context (not inside a function). Inside a function you have to specify that you want to get/set a global variable instead of a local one.

bike5

Ok the $GLOBALS['col_b'] is working. Declaring in callbike global again didn't work, it gave me an error.

So to use a global in one function in another you have to use the $GLOBALS. And if you use a global in one function but requesting it from anywhere on the page except for another function you can use global $var; Is that right?

Weedpacket

So to use a global in one function in another you have to use the $GLOBALS. And if you use a global in one function but requesting it from anywhere on the page except for another function you can use global $var; Is that right?

Globals are "in" functions - that's the point - they're floating around outside all your functions; and if you want to use them inside any function, then that function has to declare it. You can use "global $foo;" to do this, or you can take advantage of the fact that PHP maintains a list (obviously) of all of the global variables currently defined, which to you as a programmer looks like an array named $GLOBALS[].

"global $foo;" is just shorthand for saying "$foo =& $GLOBALS['foo'];", which says that $foo is an alias for the same global variable list entry that $GLOBALS['foo'] is.

But why are you using globals anyway? There's no good reason here at least.

function GetBikeInfo($table_names)
    {
        require("include/bike_cnt.php");
        require("include/session.php");
        $Query = "SELECT " . $table_names . " FROM $TableName_b WHERE bike_name='$user'";
        $Result = mysql_db_query($DBName, $Query, $Link) or die(mysql_error()); 
        return mysql_fetch_array ($Result);
    }


function CallBike()
{
require("PAGE2");
$bike_info = GetBikeInfo("*");
echo $bike_info;