JSFiddle - React, Tailwind, and code Playground

by Mottie

HTML

<div>
    <p><span id="s1">word1</span> <span id="s2">word2</span> </p>
    <div><span id="s3">word3</span> <span id="s4">word4</span></div>
    <ul>
        <li><span id="s5">word5</span> <span id="s6">word6</span></li>
    </ul>
    <p><span id="s7">word7</span> <span id="s8">word8</span> <strong><span id="s9">word9</span></strong> </p>
</div>

CSS

.red { color: red; }

JavaScript

$('div').bind('mouseup', function(){
    
    var i,
        s = window.getSelection(),
        // get ID of starting node
        start = parseInt((s.anchorNode.parentNode.id || '').substring(1), 10),
        // get ID of end node
        end = parseInt((s.extentNode.parentNode.id || '').substring(1), 10),
        // start gathering spans
        spans = $('#s' + start);

    // remove selected class
    $('span[id^=s]').removeClass('red');

    // add each span
    for (i = start; i <= end; i++) {
        spans = spans.add( $('#s' + i) );
    }
    
    // add selected class
    spans.addClass('red');
        
});