Properties of jQuery Object Instances
From jQuery
Category: Properties of jQuery Object Instances
Each jQuery object created with the jQuery() function contains a number of properties alongside its methods. These properties allow us to inspect various attributes of the object.
.context
The DOM node context originally passed to jQuery(); if none was passed then context will likely be the document.
.jquery
A string containing the jQuery version number.
.length
The number of elements in the jQuery object.