$GLOBALS 添加超全局变量

<?php
function test() {
    $foo = "local variable";

    echo '$foo in global scope: ' . $GLOBALS["foo"] . "\n";
    echo '$foo in current scope: ' . $foo . "\n";
}

$foo = "Example content";
test();
?>

结果:

$foo in global scope: Example content
$foo in current scope: local variable

$GLOBAL["变量名"];