How to inject jquery to any webpage [duplicate]

Question

Is there any way to inject jQuery into any page as we do with javascript(from url). with javascript we do this

javascript:alert("b"); 

I tried this but I don't know why it dosen't work

javascript:var x = document.getElementsByTagName("head")[0]; var y = document.createElement("script"); y.src = "http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"; x.appendChild(y);  var a = document.getElementsByTagName("body")[0]; var b = document.createElement("script"); b.innerHTML = "$('p').css('border','3px solid red')" a.appendChild(b); 

Answer 1

This is a bookmarklet code to inject jquery in any webpage:

javascript: (function (){     function l(u, i) {         var d = document;         if (!d.getElementById(i)) {             var s = d.createElement('script');             s.src = u;             s.id = i;             d.body.appendChild(s);         }     } l('//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js', 'jquery') })(); 

Update: I removed the http: part from the URL per @Monkpit comment, which is very important and saves a lot of problems.