note 71541 deleted from language.variables.scope by bjori

Note Submitter: mark (at) dreamjunky dot com Reason: in docs ---- Something to watch out for if you ever require/include files inside a function: == file1.php ======== <?php $a = 3; $b = 2; function add_them() { global $a, $b; echo $a + $b; } ?> == file2.php ======== <?php function do_it() { require ('file1.php'); add_them(); } ?> If you run file2.php, you would NOT get 5. Here's why. In file1.php, $a and $b are declared in the scope global to that file. However file2.php requires file1.php inside a function do_it(), so the variables are actually within the scope of the do_it() function. When add_them() is called and PHP encounters the line global $a, $b, there aren't any $a and $b variables in the global scope to import. Thus $a and $b are empty and $a + $b is 0. Best way to avoid this would be to avoid using globals, or not requiring/including files inside functions.