Question

<?php
session_start();
ob_start();
echo "0LIV3R 's first game";
require("DatabaseObject.php");
require("databaseVars.php");
$database= new DatabaseObject($host, $username, $password, $database);

if(!isset($_SESSION['user_id']) && $_POST['login'])
{
    $username=$database->clean($_POST['username']);
    $password=$database->clean($_POST['password']);

    $result = $database->query("SELECT 'id','username','password' FROM 'users' WHERE 'username'='$username' LIMIT 1");
    try{
        if($database->num_rows($result) == 0){
            throw new Exception('User doesnot exist!');
        }
        $user = $database->fetch($result);
        if(md5($password) != $user['password']){
            throw new Exception('Invalid username/password!');
        }
        $_SESSION['user_id'] = $user['id'];

    }catch (Exception $e){
        echo $e->getMessage();
    }
}
/*DISPLAY*/
//echo"<h3 style='text-align:center;'>WAR LEGENDS</h3>";
$output = ob_get_clean();
require('templates/header.php');
echo "<p style='text-align:center;'>". $output ."</p>";

if(!isset($_SESSION['user_id'])){
    //require('templates/layout.php');
    echo "Welcome to War Legends<br/>";
}
else{
echo"<form action='./' method='POST'>
Username: <input type='text' name='username'/><br/>
password: <input type='password' name='password'/><br/>
<input type='submit' name='login' value='Register'/>
</form>";
}
require('templates/footer.php');

?>

我试图编写在线rpg登录并在索引中出错我无法找到解决方案请帮助这是我的代码，我不知道如何解决这个问题（！）注意：未定义的索引：在第9行的C：\ wamp \ www \ myrpg \ index.php中登录这是错误

Answer 1

这意味着数组$_POST没有名为login的元素。所以请检查一下为什么会这样。可能是因为发布的表格没有这个。

Answer 2

在您使用if的第一个$_POST['login']中 - 尝试将其与!empty()或isset()函数一起使用，如下所示：!empty($_POST['login'])

第9行未定义的索引错误

2 个答案: