Usage of QUERY_STRING, REQUEST_URI in php $_SERVER

The $_SERVER function is often used in the process of writing programs. Sometimes not knowing much about variables can cause big misunderstandings. Today I found a few small examples to illustrate the usage of four commonly used variables.

$_SERVER stores the current server information, there are several values ​​​​as follows:

$_SERVER["QUERY_STRING"];

$_SERVER["REQUEST_URI"];

$_SERVER["SCRIPT_NAME"],

$_SERVER ["PHP_SELF"];

It is often easy to confuse. The following is a detailed explanation of the differences between the QUERY_STRING, REQUEST_URI, SCRIPT_NAME and PHP_SELF variables in the $_SERVER function through examples. Master the relationship between the four to facilitate the correct acquisition of the required values ​​​​in practical applications. , for reference.

1, $_SERVER["QUERY_STRING"]

Description: The string of the query

2, $_SERVER["REQUEST_URI"]

Description: The URI required to access this page

3. $_SERVER["SCRIPT_NAME"]

Description: Contains the path of the current script

4. $_SERVER["PHP_SELF"]

Description: The file name of the currently executing script

Example 1, the code is as follows:

$_SERVER["QUERY_STRING"] = ""

$_SERVER["REQUEST_URI"] = "/"

$_SERVER["SCRIPT_NAME"] = "/index.php"

$_SERVER["PHP_SELF"] = " /index.php"

Example 2, the code is as follows:

$_SERVER["QUERY_STRING"] = "tags/upload"

$_SERVER["REQUEST_URI"] = "/?tags/upload"

$_SERVER[ "SCRIPT_NAME"] = "/index.php"

$_SERVER["PHP_SELF"] = "/index.php"

Example 3, the code is as follows:

$_SERVER["QUERY_STRING"] = "tags/upload/ 2"

$_SERVER["REQUEST_URI"] = "/index.php?tags/upload/2"

$_SERVER["SCRIPT_NAME"] = "/index.php"

$_SERVER["PHP_SELF"] = "/index.php"

$_SERVER["QUERY_STRING"] obtains the query statement. As can be seen from the example, what is obtained is the value behind ?

$_SERVER["REQUEST_URI"] obtains the value behind http://www.phpfensi.com The value, including /

$_SERVER["SCRIPT_NAME"] Get the path of the current script, such as: index.php

$_SERVER["PHP_SELF"] The file name of the currently executing script

To summarize: for QUERY_STRING, REQUEST_URI , SCRIPT_NAME and PHP_SELF, an in-depth understanding will help us correctly call these four values ​​​​in the $_SERVER function. We will use examples to explain the differences between the four variables QUERY_STRING, REQUEST_URI, SCRIPT_NAME and PHP_SELF in the $_SERVER function.