Tag Archives: Javascript

jQuery Migrate Plugin

With release of 1.9 version of jQuery, many deprecated methods were discarded and they are no longer available. But there are many sites in production which are still using these deprecated features and it’s not possible to replace them overnight. So jQuery team provided with jQuery Migrate plugin that makes code written prior to 1.9 work with it.

So to use old/deprecated features, all you need to do is to provide reference of jQuery Migrate Plugin.

jQuery is not defined

There could be many reasons for this.

  • You have forgot to include the reference of jQuery library and trying to access jQuery.
  • You have included the reference of the jQuery file, but it is after your jQuery code.
  • The order of the scripts is not correct. For example, if you are using any jQuery plugin and you have placed the reference of the plugin js before the jQuery library then you will face this error.