Display PHP string with quotes and newline in Javascript (alert)

Question

PHP function addslashes allows me to escape single quotes, newlines, etc. The problem is that I can't make an actual new line in the alert box. I tried replacing backslash n by double backslash n but it will display literaly "\n" in my alert box.

<?php $this->info = "Hello ' world\nNew line"; ?>

<script type="text/javascript">
    $(document).ready(function() {
        alert('<?php echo addslashes($this->info); ?>');
    });
</script>

Answer 1

Use json_encode to create a valid JS string:

<script>
    alert(<?php echo json_encode($this->info); ?>);
</script>

Answer 2

try this

   <script>
    var myvar = <?php echo json_encode($this->info); ?>;
    alert(myvar);
  </script>