PHP 中预定义的超级全局变量和常量, 以及魔法变量

PHP 中预定义的超级全局变量和常量都是在脚本内全局可见的。

超级全局变量：

$GLOBALS

$_SERVERS

$_GET

$_POST

$_COOKIE

$_FILES

$_ENV

$_REQUEST

$_SESSION

常量：

http://php.net/manual/zh/reserved.constants.php

PHP_VERSION

PHP_OS


PHP_EOL


E_ERROR


E_ALL





Magic Variable

http://php.net/manual/en/language.constants.predefined.php

__LINE__The current line number of the file.__FILE__The full path and filename of the file with symlinks resolved. If used inside an include, the name of the included file is returned.__DIR__The directory of the file. If used inside an include, the directory of the included file is returned. This is equivalent to dirname(__FILE__). This directory name does not have a trailing slash unless it is the root directory.__FUNCTION__The function name.__CLASS__The class name. The class name includes the namespace it was declared in (e.g. Foo\Bar). Note that as of PHP 5.4 __CLASS__ works also in traits. When used in a trait method, __CLASS__ is the name of the class the trait is used in.__TRAIT__The trait name. The trait name includes the namespace it was declared in (e.g. Foo\Bar).__METHOD__The class method name.__NAMESPACE__The name of the current namespace.