Can’t add new lines in JavaScript alert Box?

I’m generating a string in PHP and then eventually passing this string into a JavaScript alert box, my problem is I actually can’t add line breaks in my alert box.

My code looks as follows

$str = "This is a stringn";
$alert = $str."This is the second line"; 

    if(!empty($alert)){
        ?>
            <script type="text/javascript">
            $(document).ready(function() {
                alert('<?=$alert?>');
            });
        </script>
    <?php
}

I’m getting the error:

Undeterminnated string literal

If I remove the n from the string it works 100% but without line breaks.

Answer

This happens because PHP interprets the n before JavaScript has the chance to, resulting in a real line break inside the Javascript code. Try

\n