admin switch case

In the code provided, there are two if statements. The second if statement displays a message IF the user role is not equal to "admin". We want to display separate messages based on the role of the logged in user. First we're going to add a message for our admin and keep the current message as the default. Step 1: Change the second if statement to a switch statement, keeping the current message as the default. Step 2: Add a second check to the switch statement for the role of "admin" and display the following message: As an admin, you can add, edit, or delete any post.

//kindly find out my error and help me to solve this problem.

<?php
//Available roles: admin, editor, author, subscriber
if (!isset($role)) {
    $role = 'subscriber';
}

//change to switch statement
switch($role){
  case 'admin':
    echo 'As an admin, you can add, edit, or delete any post';
    break;
  default:
    echo "You do not have access to this page. Please contact your administrator.";
    break;
}
?>