JSFiddle - React, Tailwind, and code Playground

HTML

<div class="row">
    <div class="myClass"></div>
</div>

<div class="row">
    <div class="myClass"></div>
</div>

<div class="row">
    <div class="notMyClass"></div>
</div>

<div class="row">
    <div class="myClass"></div>
</div>

CSS

div {
    padding: 10px;
    margin:10px;
    border: 1px solid #999;
}

div:before {
    content: '.' attr(class)
}

div.selected {
    border: 4px solid green;
}

JavaScript

var Rows = $('.row').has('> .myClass');

Rows.addClass('selected');