php - 在使用它之前是否必须检查 $_SERVER 变量中是否存在 'REQUEST_METHOD'？

Question

在实际使用 $_SERVER['REQUEST_METHOD'] 之前，我是否必须检查 $_SERVER 变量是否具有键 REQUEST_METHOD？

也就是说，总是检查数组变量中是否存在某个键是否过于防御，如 $_SERVER？

Answer 1

PHP 手册 says the following关于 $_SERVER 变量:

There is no guarantee that every web server will provide any of these; servers may omit some, or provide others not listed here. That said, a large number of these variables are accounted for in the » CGI/1.1 specification, so you should be able to expect those.

CGI/1.1 specification有以下要说的:

The REQUEST_METHOD meta-variable MUST be set to the method which
should be used by the script to process the request, as described in
section 4.3.

和

The Request Method, as supplied in the REQUEST_METHOD meta-variable, identifies the processing method to be applied by the script in
producing a response. The script author can choose to implement the
methods most appropriate for the particular application. If the
script receives a request with a method it does not support it SHOULD reject it with an error (see section 6.3.3).

如果您不进行任何 CLI 开发，则可能没有必要检查其是否存在，并且该脚本只会从 Apache 等服务器运行。为了安全起见，您可能会这样做，但没有必要这样做。