JSFiddle - React, Tailwind, and code Playground
by beebeekei
HTML
<div id='box'></div>
CSS
div {
width: 20px;
height: 20px;
}
.class1 {
background: red;
}
.class2 {
background: green;
}
.class3 {
background: orange;
}
JavaScript
var list = ['class1', 'class2', 'class3'];
document.getElementById('box').className = list[ Math.floor( Math.random() * list.length ) ];