有这些
- $GLOBALS
- $_SERVER
- $_REQUEST
- $_POST
- $_GEST
- $_FILES
- $_ENV
- $_COOKIE
- $_SESSION
$_GLOBALS
用于在函数中(或者局部作用域中)调用全局变量
$_SERVER
$_SERVER 是一个包含了诸如头信息(header)、路径(path)、以及脚本位置(script locations)等等信息的数组
由服务器创建
<?php
echo $_SERVER['PHP_SELF'];
echo "<br>";
echo $_SERVER['SERVER_NAME'];
echo "<br>";
echo $_SERVER['HTTP_HOST'];
echo "<br>";
echo $_SERVER['HTTP_REFERER'];
echo "<br>";
echo $_SERVER['HTTP_USER_AGENT'];
echo "<br>";
echo $_SERVER['SCRIPT_NAME'];
?>
$_REQUEST
PHP $_REQUEST用于收集HTML表单提交的数据