Three ways to clear session in php

This article mainly introduces three ways to clear the session in PHP. Interested friends can refer to it. I hope it will be helpful to everyone.

Session deletion and clearing is very particular. If we define it well, we can clear the specified variables. Otherwise, all sessions will be cleared accidentally. Let's take a look at some summaries.

The first way: unset($_SESSION['xxx']) deletes a single session, unset($_SESSION['xxx']) is used to unregister A registered session variable.

Its function is the same as session_unregister().

session_unregister() is obsolete in PHP5.

php official way to delete session

<?php
     // 初始化session.
     session_start();
     /*** 删除所有的session变量..也可用unset($_SESSION[xxx])逐个删除。****/
     $_SESSION = array();
     /***删除sessin id.由于session默认是基于cookie的，所以使用setcookie删除包含session id的cookie.***/
     if (isset($_COOKIE[session_name()])) {
        setcookie(session_name(), &#39;&#39;, time()-42000, &#39;/&#39;);
     }
     // 最后彻底销毁session.
     session_destroy();
?>

unset($_SESSION) This function must not be used, it will destroy the global variable $_SESSION, and it is not feasible yet method to restore it. Users can no longer register the $_session variable either.

Second method: session_unset() or $_SESSION=array() to delete multiple sessions

Three ways: session_destroy() ends the current session and clears all resources in the session. This function will not unset (release) global variables related to the current session, nor will it delete the client's session cookie. PHP's default session is based on cookies. If you want to delete cookies, you must use the setcookie() function.

Summary:

session_destroy is to log out all session variables and end the session session;

If you want to delete some session data, you can use the unset() function or session_destroy( )function. The function of unset() function is to release the specified session variable. The calling format is as follows:

<?php
unset($_SESSION[&#39;jugelizi&#39;]);
?>

session_destroy() function is to delete all sessions. The calling format is as follows:

<?PHP session_destroy(); ?>

Tip: session_destroy () will reset the session and you will lose all saved session data.

session_unset() does not unregister the session variables, but clears the values ​​of all session variables.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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