Jquery Check if Selector Null

jQuery: Handy selector null check

In jQuery, if you want to check if a selector exists or not you could check the length property, or use the size method.

if($('#nothing').length === 0) console.log('Nothing');
if($('#nothing').size() === 0 ) console.log('Nothing');
if($('#nothing').get(0) === undefined ) console.log('Nothing');
if($('#nothing')[0] === undefined ) console.log('Nothing');

However, by extending the fn with a simple method we can get some nice flow.

$.fn.exists = function(){
    return this.length > 0 ? this : false;

Then, we can use it like follows:

var $el = $('#nothing').exists()   || // false
          $('#something').exists() || // assign value
          $('#neverHere').exists();   // never gets here.