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Variable scope mystery

P: n/a
Here is a nice problem. I have two scripts, one calling the other with via
an include. The script that is included contains a variable, a function and
a call to that function. The variable needs to be accessible to the
function, so I declare it having a global scope. Then I execute the
function, which should echo the value of the variable. Contrary to what I
expected, the variable isn't there.

The code of the 2 programs is:

script1.php
<?php
function blah()
{
include("script2.php");
}

blah();
?>

script2.php
<?php
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

I can't see anything wrong with the way I set this up, even more since a
call to script2.php does exactly what it's suppossed to do: echo the value.
What's going on here is beyond me. Anybody has a clue?

Kind regards, Maarten
Nov 22 '05 #1
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6 Replies


P: n/a
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Hash: SHA1

Maarten wrote:
Here is a nice problem. I have two scripts, one calling the other with via
an include. The script that is included contains a variable, a function and
a call to that function. The variable needs to be accessible to the
function, so I declare it having a global scope. Then I execute the
function, which should echo the value of the variable. Contrary to what I
expected, the variable isn't there.

The code of the 2 programs is:

script1.php
<?php
function blah()
{
include("script2.php");
}

blah();
?>

script2.php
<?php
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

I can't see anything wrong with the way I set this up, even more since a
call to script2.php does exactly what it's suppossed to do: echo the value.
What's going on here is beyond me. Anybody has a clue?

Kind regards, Maarten


I can... you can't expect to include another function within blah();

To do it, use a class, and include your blahblah(); and just use blah();
to reference to it within your class::function();
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Nov 22 '05 #2

P: n/a
daemon said the following on 18/11/2005 16:43:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Maarten wrote:
Here is a nice problem. I have two scripts, one calling the other with via
an include. The script that is included contains a variable, a function and
a call to that function. The variable needs to be accessible to the
function, so I declare it having a global scope. Then I execute the
function, which should echo the value of the variable. Contrary to what I
expected, the variable isn't there.

The code of the 2 programs is:

script1.php
<?php
function blah()
{
include("script2.php");
}

blah();
?>

script2.php
<?php
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

I can't see anything wrong with the way I set this up, even more since a
call to script2.php does exactly what it's suppossed to do: echo the value.
What's going on here is beyond me. Anybody has a clue?

Kind regards, Maarten

I can... you can't expect to include another function within blah();


Yes you can.

The problem is that by declaring $foo = "bar" in what intuitively looks
like the global scope within script2.php, it's actually being declared
in the scope of blah(), and therefore isn't a global variable, and
therefore can't be accessed within blahblah().

Change script2.php to:

<?php
global $foo;
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

--
Oli
Nov 22 '05 #3

P: n/a
Thank you for replying, but you are mistaking. This for example works fine,
even when the second function is included from an outside file.

function blah()
{
function blahblah()
{
echo "foo";
}
blahblah();
}
blah();

"daemon" <d4****@shaw.ca> wrote in message
news:cxnff.523697$oW2.516262@pd7tw1no...
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Maarten wrote:
Here is a nice problem. I have two scripts, one calling the other with
via
an include. The script that is included contains a variable, a function
and
a call to that function. The variable needs to be accessible to the
function, so I declare it having a global scope. Then I execute the
function, which should echo the value of the variable. Contrary to what I
expected, the variable isn't there.

The code of the 2 programs is:

script1.php
<?php
function blah()
{
include("script2.php");
}

blah();
?>

script2.php
<?php
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

I can't see anything wrong with the way I set this up, even more since a
call to script2.php does exactly what it's suppossed to do: echo the
value.
What's going on here is beyond me. Anybody has a clue?

Kind regards, Maarten


I can... you can't expect to include another function within blah();

To do it, use a class, and include your blahblah(); and just use blah();
to reference to it within your class::function();
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Version: GnuPG v1.4.2 (MingW32)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFDfmZh/WE0aXnOUiYRAmpQAJ4gbRQBepMOTriilvr82GryQuykTQCgk0T Z
tZ637ZaemoIUKhM4n4Frh2w=
=f1n2
-----END PGP SIGNATURE-----

Nov 22 '05 #4

P: n/a
Yes, that's it! So, a variable declared inside a function isn't available
inside nested function even while you are calling it in (global). You'll
have to declare it global in the main function first. This can cause
problems though, as there might be a variable with the same name outside the
main function that you do not want to access. See what I mean? The solution
is obvious of course, but sometimes you just don't know what variables live
out there, do you?
"Oli Filth" <ca***@olifilth.co.uk> wrote in message
news:YT******************@newsfe6-gui.ntli.net...
daemon said the following on 18/11/2005 16:43:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Maarten wrote:
Here is a nice problem. I have two scripts, one calling the other with
via an include. The script that is included contains a variable, a
function and a call to that function. The variable needs to be accessible
to the function, so I declare it having a global scope. Then I execute
the function, which should echo the value of the variable. Contrary to
what I expected, the variable isn't there.

The code of the 2 programs is:

script1.php
<?php
function blah()
{
include("script2.php");
}

blah();
?>

script2.php
<?php
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

I can't see anything wrong with the way I set this up, even more since a
call to script2.php does exactly what it's suppossed to do: echo the
value. What's going on here is beyond me. Anybody has a clue?

Kind regards, Maarten

I can... you can't expect to include another function within blah();


Yes you can.

The problem is that by declaring $foo = "bar" in what intuitively looks
like the global scope within script2.php, it's actually being declared in
the scope of blah(), and therefore isn't a global variable, and therefore
can't be accessed within blahblah().

Change script2.php to:

<?php
global $foo;
$foo = "bar";

function blahblah()
{
global $foo;
echo $foo;
}

blahblah();
?>

--
Oli

Nov 22 '05 #5

P: n/a
Maarten said the following on 18/11/2005 17:28:
Yes, that's it! So, a variable declared inside a function isn't available
inside nested function even while you are calling it in (global). You'll
have to declare it global in the main function first. This can cause
problems though, as there might be a variable with the same name outside the
main function that you do not want to access. See what I mean? The solution
is obvious of course, but sometimes you just don't know what variables live
out there, do you?


I think the solution is: Don't use global variables!

Always explicitly pass required variables to functions.

--
Oli
Nov 22 '05 #6

P: n/a
What can I say? You are right of course. Thanks you very much for your help.

Regards, Maarten

"Oli Filth" <ca***@olifilth.co.uk> wrote in message
news:Lb******************@newsfe6-gui.ntli.net...
Maarten said the following on 18/11/2005 17:28:
Yes, that's it! So, a variable declared inside a function isn't available
inside nested function even while you are calling it in (global). You'll
have to declare it global in the main function first. This can cause
problems though, as there might be a variable with the same name outside
the main function that you do not want to access. See what I mean? The
solution is obvious of course, but sometimes you just don't know what
variables live out there, do you?


I think the solution is: Don't use global variables!

Always explicitly pass required variables to functions.

--
Oli

Nov 22 '05 #7

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