"* RECURSION *"是什么意思?打印$ GLOBALS时是什么意思? [英] What does "*RECURSION*" mean when printing $GLOBALS?

问题描述

当我使用此代码打印$GLOBALS时:

When I print $GLOBALS using this code:

<?php print_r($GLOBALS); ?>

我得到以下输出:

Array ( [_GET] => Array ( ) [_POST] => Array ( ) [_COOKIE] => Array ( ) [_FILES] => Array ( ) [GLOBALS] => Array *RECURSION* )

在这种情况下，"*RECURSION*"是什么意思?为什么不同时打印$_SERVER，$_REQUEST等?

What does "*RECURSION*" mean in this case, and why are $_SERVER, $_REQUEST, etc. not printed as well?

推荐答案

请参见

请记住，$ GLOBALS本身就是一个全局变量.因此，这样的代码将行不通:

Keep in mind that $GLOBALS is, itself, a global variable. So code like this won't work:

<?php
    print '$GLOBALS = ' . var_export($GLOBALS, true) . "\n";
?>

这会导致错误消息:嵌套级别太深-递归依赖项?"

This results in the error message: "Nesting level too deep - recursive dependency?"

您已经检索了整个列表-您无法显示其中的一部分(包含递归的列表，因为您可能会超时而不是有意义的事情).

You already have retrieved the whole list - you just cannot display part of it (the one containing a recursion, because you would have timeout rather than anything meaningful).

对于$_REQUEST，它是$_GET，$_POST和$_COOKIE的派生词，因此其内容是多余的.

When it comes to $_REQUEST, it is a derivative from $_GET, $_POST and $_COOKIE, so its content is redundant.

编辑:有一个旧的错误/功能，访问它们时似乎在$GLOBALS中填充了$_SERVER和$_REQUEST.因此，尝试访问$_REQUEST，希望对您有所帮助.无论如何，之后都可以在$GLOBALS中找到它:ideone.com/CGetH

EDIT: There is an old bug / feature, that seems to be populating $GLOBALS with $_SERVER and $_REQUEST when they are accessed. So try to access $_REQUEST and hope it helps. Anyway, it can be found in $GLOBALS after that: ideone.com/CGetH

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