Can't add new lines in JavaScript alert Box?

Question

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 string\n";
$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 string it works 100% but without line breaks

Answer 1

Have you tried \r\n?

Answer 2

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

Answer 3

You need to change $str to

$str = "This is a string\\n";

so that the \n gets passed to the javascript.