JSFiddle - React, Tailwind, and code Playground
HTML
<div class="whatever">
world wide web
</div>
<div class="whatever">
world wide web
</div>
<div class="whatever">
world wide web
</div>
<div class="whatever">
world wide web
</div>
CSS
span {
color: red;
}
JavaScript
$('.whatever').each(function() {
var mystring = $(this).html();
mystring = mystring.replace(/e/g, "<span>e</span>");
$('.whatever').html(mystring);
});