JSFiddle - React, Tailwind, and code Playground

HTML

<p>Lorem ipsum dolor sit amet, mariae Bone de me in deinde vero diam nostra paupercula possunt autem quod una. Percussus ait in fuerat construeret cena reges undis effugere quod una.</p>

CSS

.selected{
background-color:#FF00FF;
}

JavaScript

var selection = "n";
var spn = '<span class="selected">'+selection+'</span>';
$("p").html($("p").html().replace(selection,spn));