How to use session in session control in PHP?

The previous article introduced to you "What are the vulnerabilities of commonly used functions in PHP? 》, this article continues to introduce to you how to use session in session control in PHP? It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

Session control (use of session)

How to use session

The operation of session is exactly the same as the operation of array.

If you use session in the page, you must first open the session (session_ start()) session at the beginning of the page.

Set or get sess ionid; through function sessionid();

Add session

- $ SESSION['下标'] -值;

Modify session

$ SESSION['下标'] -新值;

Delete session

1. Delete the variable value of the session (retain the data type)

$ SESSION - array();

2. Delete all session information (including files) - generally used for exit operations

1. Make the SESSIONID in the client COOKIE Expired.

2. Clear the variable value of page SESSION

3. Destroy the SESSION file of the server

使用session
查看全部SESSION信息
var_ dump( )或者print_ r(); 
使用其中sesssion的某个元素
$_ SESSION[下标];|

First we create a new page (login page), and then create a new PHP page

1得到用户输入的用户名和密码
2.然后在数据库中查询是否有该用户的存储
//$sql = "SELECT id FROM user WHERE name=用户 输入的用户名&& 
pwd=等于用户输入的密码加密后的字符串”; 
//有数据 密码正确登录成功
//没有数据
提示用户名或密码错误
请注册

Then we create a new file (1.PHP): the code is as follows

<?php
  if(isset($_SESSION[&#39;user&#39;][&#39;islogin&#39;]) && $_SESSION[&#39;user&#39;][
&#39;islogin&#39;] == true){
//已经登录
echo &#39;亲爱的&#39;. $_SESSION[&#39;user&#39;][&#39;name&#39;]. &#39;会员，欢迎您回来<br/>&#39; ;
echo &#39;这是a页面<br/>&#39;;
echo &#39;<a href="index . php">去首页</a><br/>&#39;;
echo &#39;<a href="b. php">去b页面</a><br/>&#39;;
echo &#39;<a href="c . php" >去c页面</a><br/>&#39;;
}else{
//用户没有登录
echo &#39; 对不起，您无权访问3S后自动跳转到登录页面&#39; ;
echo &#39; <meta http- equiv=" refresh"
       content="3;url=./login. html">&#39; ;
}

Then we create a new file (2.PHP): the code As follows

<?php
  if(isset($_SESSION[&#39;user&#39;][&#39;islogin&#39;]) && $_SESSION[&#39;user&#39;][
&#39;islogin&#39;] == true){
//已经登录
echo &#39;亲爱的&#39;. $_SESSION[&#39;user&#39;][&#39;name&#39;]. &#39;会员，欢迎您回来<br/>&#39; ;
echo &#39;这是2页面<br/>&#39;;
echo &#39;<a href="index . php">去首页</a><br/>&#39;;
echo &#39;<a href="b. php">去b页面</a><br/>&#39;;
echo &#39;<a href="c . php" >去c页面</a><br/>&#39;;
}else{
//用户没有登录
echo &#39; 对不起，您无权访问3S后自动跳转到登录页面&#39; ;
echo &#39; <meta http- equiv=" refresh"
       content="3;url=./login. html">&#39; ;
}

Then we create a new file (3.PHP): The code is as follows

<?php
  if(isset($_SESSION[&#39;user&#39;][&#39;islogin&#39;]) && $_SESSION[&#39;user&#39;][
&#39;islogin&#39;] == true){
//已经登录
echo &#39;亲爱的&#39;. $_SESSION[&#39;user&#39;][&#39;name&#39;]. &#39;会员，欢迎您回来<br/>&#39; ;
echo &#39;这是3页面<br/>&#39;;
echo &#39;<a href="index . php">去首页</a><br/>&#39;;
echo &#39;<a href="b. php">去b页面</a><br/>&#39;;
echo &#39;<a href="c . php" >去c页面</a><br/>&#39;;
}else{
//用户没有登录
echo &#39; 对不起，您无权访问3S后自动跳转到登录页面&#39; ;
echo &#39; <meta http- equiv=" refresh"
       content="3;url=./login. html">&#39; ;
}

Then we create a new file (index. PHP): The code is as follows

<?php
//var_dump($_COOKIE);
//这是项目的首页
if(isset($_SESSION[ &#39;user&#39; ][&#39;islogin&#39;]) && $_SESSION[&#39;user&#39;][
 &#39;islogin&#39;] == true){
//已经登录
echo &#39;亲爱的&#39;.$_ SESSION[ &#39;user&#39;][ &#39;name&#39; ].&#39;会员,欢迎您回来<br/>&#39; ;
echo &#39;<a href="1.php">去1页面</a><br/>&#39;;
echo &#39;<a href= "2.php" >去2页面</a><br/>&#39;;
echo &#39;<a href="3.php">去3页面</a><br/>&#39;;
}else{
//用户没有登录
echo &#39;对不起，您无权访问3S后自动跳转到登录页面&#39; ;
echo &#39;<meta http- equiv=" refresh"
content="3;url=./login. html">&#39;;
}

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to use session in session control in PHP?. For more information, please follow other related articles on the PHP Chinese website!