php - $_REQUEST 优先级是什么？

Question

PHP 超全局变量

PHP 具有可以在脚本的任何范围内访问的全局变量。其中三个变量($_GET、$_POST、$_COOKIE)存储在第四个变量($_REQUEST >).

$_GET

An associative array of variables passed to the current script via the URL parameters.

考虑以下发送和访问 URL 的示例。

http://www.example.com/myPage.php?myVar=myVal

echo $_GET["myVar"]; // returns "myVal"

$_POST

An associative array of variables passed to the current script via the HTTP POST method when using application/x-www-form-urlencoded or multipart/form-data as the HTTP Content-Type in the request.

使用的示例如下。

<form action="somePage.php" method="POST">
    <input type="text" name="myVar" value="myVal" />
    <input type="submit" name="submit" value="Submit" />
</form>

echo $_POST["myVar"]; // returns "myVal"

$_COOKIE

An associative array of variables passed to the current script via HTTP Cookies

setcookie("myVar", "myVal", time() + 3600);
echo $_COOKIE["myVar"]; // returns "myVal"

$_REQUEST

An associative array that by default contains the contents of $_GET, $_POST and $_COOKIE.

---

事情是这样的

$_REQUEST 在一个数组中包含所有三个，可通过 $_REQUEST["myVar"] 访问。

随机场景

让我们假设，无论出于何种原因，我对我的 $_GET、$_POST 和 $_COOKIE 使用相同的名称。

$_REQUEST 中存储的内容的优先级是什么。

假设我通过 URL 设置发送数据，通过表单发布，并设置一个彼此同名的 cookie(我知道这是一个奇怪的场景)。
假设我使用了名称“example”。

下面的输出结果是什么？

     if ($_REQUEST["example"] == $_GET["example"])    echo "GET";
else if ($_REQUEST["example"] == $_POST["example"])   echo "POST";
else if ($_REQUEST["example"] == $_COOKIE["example"]) echo "COOKIE";

tl;dr

如果$_GET、$_POST 和$_COOKIE 都存储了同名的值； $_REQUEST 将以所述名称存储哪一个？

Answer 1

在 php.ini 文件中有 2 个指令:request_order 和 variables_order

request_order string

This directive describes the order in which PHP registers GET, POST and Cookie variables
into the _REQUEST array. Registration is done from left to right, newer values override 
older values.

If this directive is not set, variables_order is used for $_REQUEST contents.

Note that the default distribution php.ini files does not contain the 'C' for cookies, 
due to security concerns.

和

variables_order string

Sets the order of the EGPCS (Environment, Get, Post, Cookie, and Server) variable 
parsing. For example, if variables_order is set to "SP" then PHP will create the 
superglobals $_SERVER and $_POST, but not create $_ENV, $_GET, and $_COOKIE. Setting 
to "" means no superglobals will be set.

If the deprecated register_globals directive is on, then variables_order also configures 
the order the ENV, GET, POST, COOKIE and SERVER variables are populated in global scope. 
So for example if variables_order is set to "EGPCS", register_globals is enabled, and both 
$_GET['action'] and $_POST['action'] are set, then $action will contain the value of 
$_POST['action'] as P comes after G in our example directive value.

取自official documentation