How to remove null from my Javascript

Question

So, here's my script:

$(function () {
   // define this here because we're changing the ID
   var $twitter = $('twitter');
   // bind to select inside iframe
    $('#iframe').on('load', function () {
      $(this).contents().find('#cds').change(function () {
         var selectVal = $(this).val();
         url = 'https://twitter.com/intent/tweet?button_hashtag=stream&text=Just enjoying ' + selectVal + ' on';
        $twitter.attr("id", url);
    }).change(); // trigger change to get initial value
  });
});

Basically, it takes the selected value from my select box, and outputs it into a twitter link. The problem is, when nothing is selected, it outputs "null", and I was wondering if there was a way to detect this, and echo something else.

Answer 1

Try this:

var selectVal = $(this).val() || 'default value';