JSFiddle - React, Tailwind, and code Playground

by ramsesoriginal

HTML

<a href="a">A</a>
<a href="b">B</a>
<a href="a">A</a>
<a href="c">C</a>

CSS

a:before
{
content:attr(data-counter)". ";
}

JavaScript

var linkcounter = {};
var counter = 0;
$("a").each(function() {
    if (!linkcounter.hasOwnProperty($(this).attr("href"))) {
        counter++;
        linkcounter[$(this).attr("href")] = counter;
    }
    $(this).attr("data-counter", linkcounter[$(this).attr("href")]);
});
alert(counter);