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# Handling of global variables

While handling of global variables had the focus on to be easy in PHP 3 and early versions of PHP 4, the focus has changed to be more secure. While in PHP 3 the following example worked fine, in PHP 4 it has to be unset($GLOBALS["id"]);. This is only one issue of global variable handling. You should always have used $GLOBALS, with newer versions of PHP 4 you are forced to do so in most cases. Read more on this subject in the `global` references section.

Example B-1. Migration of global variables
    <?php
    $id = 1;
    function test()
    {
        global $id;
        unset($id);
    }
    test();
    echo($id); // This will print out 1 in PHP 4
    ?>

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