Prevent User from accessing admin.php - php

Question

I'm having a problem preventing regular users from accessing my admin.php page.
I've set in the database it so that users have a type (it's a boolean so either 0 = admin or 1 = normal user)
At the top of my admin.php page I have
<?php
// Initialize the session
session_start();
// Check if the user is logged in, if not then redirect him to login page
if(!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] !== true){
header("location: login.php");
}
elseif(!isset($_SESSION['type']) && $_SESSION['type'] !== 0) {
header('Location: profile.php');
exit;
}
?>
I originally had the last piece of code as:
elseif(!isset($_SESSION['type']) || $_SESSION['type'] !== 0) {
header('Location: profile.php');
exit;
but this would prevent all users, both admin or normal, from accessing the admin page. I'm not sure how to proceed.
Edit: I'm a novice at PHP and still a student so I'm not 100% familiar with PHP.

Answer 1

Correct code is:
// Check if the user is logged in
if(!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] == true){ // if login
if(!isset($_SESSION['type']) && $_SESSION['type'] == 0){ //if admin (type == 0)
header('Location: profile.php');
}
else{ //if not admin (type !== 0)
header('send somewhere else');
}
}
else { // else not login
header('Location: login.php');
exit;
}

Answer 2

Since you're a novice at PHP, what I'm going to recommend is not an answer to fix your code (I don't see any obvious problem with it), but instead how to set up your development environment so that you can easily see what the problem is yourself.
There are two main options:
1.) (Best option) Setup Xdebug and an IDE so that you can debug your code in real time, line by line
2.) Use echo to output information to the page
Option #1
This is the best option, and I highly recommend you learn how to debug PHP line by line, as soon as you can. Xdebug is the most popular debugger for PHP; you'll need to set that up and install it. Then you'll need an IDE that supports debugging. I recommend PHPStorm if you have the funds, or Sublime Text if you need a free option.
Option #2
Instead of having your code redirect, have it output information, like this:
$loggedIn = isset($_SESSION["loggedin"]);
echo $loggedIn;
$type = $_SESSION['type'];
echo $type;
This is kind of the "poor mans" debugging. It allows you to see printed to the page, what the values of variable are. Once you know what the values are, you'll easily be able to figure out why your code isn't working. You can even then do things like this:
elseif(!isset($_SESSION['type']) && $_SESSION['type'] !== 0) {
echo "this will take you to profile.php";
}