How can PHP be used to restrict access to user details based on user roles or permissions?

To restrict access to user details based on user roles or permissions in PHP, you can implement role-based access control (RBAC) by checking the user's role or permissions before displaying the user details. This can be achieved by storing user roles or permissions in a database and validating them against the current user's role. If the user does not have the necessary role or permissions, you can redirect them to a different page or display an error message.

// Check user's role or permissions before displaying user details
if($userRole !== 'admin') {
    // Redirect user to a different page or display an error message
    header('Location: unauthorized.php');
    exit();
}

// Display user details
echo "User details: Name, Email, etc.";