How can PHP developers ensure user-friendly error messages when utilizing JavaScript alerts for notifications?

When utilizing JavaScript alerts for notifications in PHP applications, developers can ensure user-friendly error messages by passing the error message as a parameter to the JavaScript alert function. This way, the error message will be displayed in a pop-up alert dialog, providing a clear and visible notification to the user.

<?php
$error_message = "An error has occurred. Please try again.";
echo "<script>alert('$error_message');</script>";
?>