Php, global variables on two external scripts

Question

How would I pass a global var in two external scripts?

<div>
<!-- INCLUDEPHP 1.php -->
</div>
<div>
<!-- INCLUDEPHP 2.php -->
</div>

I have tried creating global variables on 1.php and `2.phpp but it didn't work.

1.php:

<?php
global $someVar;
$sql = ...;
$someVar= $db -> sql_query($sql);
?>

2.php:

<?php
global $someVar;
echo "$someVar";
?>

Am I doing something wrong?

I don't think you should not be using Global variables(not good practice). You could potentially use $_SESSION, to undertake what you require though. — Haroon
– Haroon, Commented Jun 10, 2012 at 20:46
@Haroon: NO NO NO NO NO! Don't use session just to communicate between scripts when building a page! — Eric
– Eric, Commented Jun 10, 2012 at 20:47
@wtsang02 can you give the exact code, im a little confused, if its local a normal var will work in an included file. — user557846
– user557846, Commented Jun 10, 2012 at 20:50

Eric · Accepted Answer · 2012-06-10 20:47:50Z

2

I would try including the scripts via PHP:

<div>
<?php require "1.php" ?>
</div>
<div>
<?php require "2.php" ?>
</div>

answered Jun 10, 2012 at 20:47

Eric

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4 Comments

Eric Over a year ago

@wtsang02: What were you doing before‽ Was  your actual code?

user557846 Over a year ago

so the issue was, the syntax for include, noting to do with variables?

PeeHaa Over a year ago

@Eric Not enough global -1 ;-)

RomanPerekhrest Over a year ago

when including scripts, require_once is preferable to check if the file has been already included

mtf · Accepted Answer · 2012-06-10 21:11:53Z

If both includes are loaded into the same page, and the variables exist already in the global scope, all your functions can access them with the global statement. Since everything is already global, the statement is not required in the global scope, only inside functions. This also permits functions to share variables by casting them onto the global scope.

There are many dangers to this, though, which I'll not pretend to be fully aware of, so one is best advised to make prudent use of the global scope in large complex applications as they can become very volatile if naming conventions are relaxed.

Basically, we're looking at,

function arrow() { global $a; $a = "arrow"; return $a; }
function sky() { global $b; $b = "sky"; return $b; }
echo "I shot an " . arrow() . " into the " . sky() . ".";
echo "I shot an $a into the $b.";

which is child's play, it demonstrates how exposed the variables are, sitting out there with no protection. Now another function can come along and blow the whole thing apart:

function whammo() { global $a, $b; $c = $a; $a = $b; $b = $c;}
echo "I shot an " . arrow() . " into the " . sky() . ".";
whammo();
echo "I shot an $a into the $b.";

See what I mean?

Your solution probably lies in a closure of some sort, wherein all the functions are contained that need this 'global'. It will be much better protected.

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