global variables in php not working as expected

Question

I\'m having trouble with global variables in php. I have a $screen var set in one file, which requires another file that calls an initSession() def

Answer 1

Global DOES NOT make the variable global. I know it's tricky :-)

Global says that a local variable will be used as if it was a variable with a higher scope.

E.G :

<?php

$var = "test"; // this is accessible in all the rest of the code, even an included one

function foo2()
{
    global $var;
    echo $var; // this print "test"
    $var = 'test2';
}

global $var; // this is totally useless, unless this file is included inside a class or function

function foo()
{
    echo $var; // this print nothing, you are using a local var
    $var = 'test3';
}

foo();
foo2();
echo $var;  // this will print 'test2'
?>

Note that global vars are rarely a good idea. You can code 99.99999% of the time without them and your code is much easier to maintain if you don't have fuzzy scopes. Avoid global if you can.