How to inject jquery to any webpage

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('//code.jquery.com/jquery-3.2.1.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.