JSFiddle - React, Tailwind, and code Playground

HTML

<div class="delete-confirm"></div>
<div class="s-delete-confirm"></div>
<div class="3-delete-confirm ddd"></div>
<div class="abc 2-delete-confirm"></div>
<div class="abc 2-delete-confirm ccc"></div>
<div class="abc 2-delete-confirms ccc"></div>

JavaScript

var regExp = /-delete-confirm(\s|$)/;

var $allofthem = $('div').filter(function(){
    return regExp.test(this.className) || $(this).is('.delete-confirm');
});

alert($allofthem.length);