jQuery.fn.jquery

jQuery.fn.jquery gives you the current version

Self executing script (function (){/* Your stuff here *?})(); code is self-executing function.

JavaScript code for inserting jquery link for a HTML Page

javascript:if(!window.jQuery||confirm("Do\x20you\x20want\x20to\x20overwrite\x20existing\x20version"))(function(d,s){s=document.createElement('script');s.src="https://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.js";(d.head||d.documentElement).appendChild(s);})(document);