使用isset php函数确定是否在超级全局会话数组中设置了密钥

Question

I have a page called login.php. Login.php processes user information. If the passed user information is found in the database a new session is started. The name and password are then added to the super global sessions array

if(correct_password($name, $password, $users, $users_size)) {
session_start();
$_SESSION["name"] = $name;
$_SESSION["password"] = $password;
header("Location: account.php");

After the validation the user is redirected to account.php. I want to ensure that the user is logged in i.e the "name" index is set before they can access account.php. In order to do this I have the following code

if(!isset($_SESSION["name"])) {
    header("Location: index.php");
    die;
}

This code is suppose to check to see if the "name" index is set. If it is not set it means the user is not logged in and should therefore be directed back to index.php. However it seems that even if the user logs in the if always is true. I even tested

echo isset($_SESSION["name"]);
die;

to simplify things. When this is done nothing appears on the screen meaning that isset evaluated to false. If I try to print the global sessions array in account.php it works. The data prints and it shows that the name field is populated with the data submited from login.php.

What am I misunderstanding about isset? Or did I mess up somewhere else.

Thanks in advance.

Answer 1

You also need to have session_start(); on top of the page where you check for that value, not only where you set it.

session_start();
if(!isset($_SESSION["name"])) {
    header("Location: index.php");
    die;
}