3 else or 2 if?

Question

PHP

In general, I have a header, it should contain info for an unregistered user, for a regular user and for an admin. Users have user_group- where 1 is admin, 5 is a regular user.
So I decided for not logged in and logged in

if(empty ($_SESSION['username']) or empty ($_SESSION['id'])){
echo'
<div id="header">

</div>
';
}else{
echo'
<div id="header">
<a href="/">главная</a>
</div>
';
}

It is necessary that the admin sees all this, and also his own elements, such as the control panel

Answer 1

It is possible to take out still obtaining of group of the user.

switch (true):
    case ($_SESSION['user_group'] ?? null) === 1:
        // admin
        break;
    case ($_SESSION['user_group'] ?? null) === 5:
        // user
        break;
    default:
        // guest
        break;
endswitch;

Answer 2

To avoid torment: wrap, for example, getting a group into a function or method, and then more concisely iterate through switch:

function getUserGroup() {
//..
}
switch(getUserGroup()) {
  case 'admin': 
    break;
  case 'user': 
    break;
  case 'guest':
  default: 
    break;
}

Answer 3

<div id="header">
<?php
if(empty ($_SESSION['username'] or empty ($_SESSION['id'])){

}else{
echo'
<a href="/">главная</a>
';
} elseif($_SESSION['username']['is_admin'] == true) {
echo 'admin';
}
?>
</div>

Answer 4

1. We get the user group not from the session, but from the database
2. Display the required html block as you like, but not through nested if