请注意，我一直在尝试解决此问题，但效果不佳。我已经启动了一个会话，但在使用unset($_SESSION['variable']注销后，由于未设置会话，我无法重新登录。
请帮帮我。注意：在取消设置变量后，我无法登录。
//this is login.php
<?php
session_start();
ob_start();
$msg = "";
if (isset($_POST['login'])){
include "dbconnect.php";
if($_SESSION['emaill'] !== NULL){
$emaill= $_SESSION['emaill'];
$passWord = $_POST['passWord'];
if (empty($emaill && $passWord) == false){
$sql = "SELECT * FROM `sono` WHERE `eMail`='$emaill' && `passWord`='$passWord'";
$check = mysqli_query($dbconnect, $sql) or die (mysqli_error($dbconnect));
$result = mysqli_num_rows($check);
if ($result > 0){
$emaill= $_SESSION['emaill'];
header ('location: home.php');
exit();
} else
$msg = "<p style='color: red; padding-left: 10px'>Invalid password or email address</p>";
} else
$msg = "<p style='color: red; padding-left: 10px'>Please enter your email and password to login</p>";
} else
$msg = "<p style='color: red; padding-left: 10px'>My scripts not working yet</p>";
}
?>
// this is for logout
<?php
session_start();
if (isset($_SESSION['emaill'])){
unset($_SESSION['emaill']);
header('location: login.php');
}
?>
在使用$_SESSION['email']之前，请使用isset（）进行检查，如：
if( isset($_SESSION['emaill']) && $_SESSION['emaill'] !== NULL){
----
---
}
在此处添加isset检查
if(isset($_SESSION['emaill']) && $_SESSION['emaill'] !== NULL){
您可以在SESSION之前使用空函数来检查值是否存在。由于变量在注销时未设置或已销毁，因此在登录时无法识别SESSION。你可以尝试如下检查：-
if(!empty($_SESSION['emaill']))
{
// Your code here
}