How to delete session_id in php

In PHP, you can use the unset() function to delete "session_id". This function can destroy the given variable. The syntax format is "unset($_SESSION['session_id']);".

The operating environment of this tutorial: Windows 7 system, PHP version 7.1, DELL G3 computer

To delete a session value, you can use PHP's unset After the function is deleted, it will be removed from the global variable $_SESSION and cannot be accessed.

session_start();
$_SESSION['name'] = 'jobs';
unset($_SESSION['name']);
echo $_SESSION['name']; //提示name不存在

If you want to delete all sessions, you can use the session_destroy function to destroy the current session. session_destroy will delete all data, but the session_id still exists.

session_start();
$_SESSION['name'] = 'jobs';
$_SESSION['time'] = time();
session_destroy();

It is worth noting that session_destroy will not immediately destroy the value in the global variable $_SESSION. Only when it is accessed next time, $_SESSION will be empty. Therefore, if you need to destroy $_SESSION immediately, you can Use the unset function.

session_start();
$_SESSION['name'] = 'jobs';
$_SESSION['time'] = time();
unset($_SESSION);
session_destroy(); 
var_dump($_SESSION); //此时已为空

If you need to destroy the session_id in the cookie at the same time, which may be used when the user logs out, you also need to explicitly call the setcookie method to delete the cookie value of the session_id.

Task

Use unset to delete the session value of name.

<?php
session_start();
$_SESSION[&#39;name&#39;] = &#39;jobs&#39;;
//在这里删除name的session值
unset($_SESSION[&#39;name&#39;]);
if (isset($_SESSION[&#39;name&#39;])) {
    echo $_SESSION[&#39;name&#39;];
    return;
}

  echo &#39;session被销毁&#39;;

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