- stripslashes: documentation ( source)
<?php
$a = "{\"name\":\"HTML\",\"html\":\"<script type=\"text\\\/javascript\">\\r\\ngform.addFilter( 'gform_product_total', function(total, formId){\\r\\n return total; \\\/\\\/amount you wish to display in the Total \\r\\n } );\\r\\n<\\\/script>\",\"hidden\":\"0\",\"columns\":\"6\",\"e_id\":\"12\"}";
echo stripslashes($a);