JSFiddle - React, Tailwind, and code Playground

by Sub Lines

HTML

<div class="thumbnail">One</div>
<div class="thumbnail">Two</div>
<div class="thumbnail">Three</div>
<div class="thumbnail">Four</div>
<div class="thumbnail">Five</div>
<div class="thumbnail">Six</div>
<div class="thumbnail">Seven</div>
<div class="thumbnail">Eight</div>

JavaScript

// Shuffle array function
function shuffle(array) {
    var counter = array.length, temp, index;

    // While there are elements in the array
    while (counter--) {
        // Pick a random index
        index = (Math.random() * counter) | 0;

        // And swap the last element with it
        temp = array[counter];
        array[counter] = array[index];
        array[index] = temp;
    }

    return array;
}

// DOM ready
$(function () {
    // select elements
    var items = $('.thumbnail');
    var randomized = shuffle(items).slice(0, 3);
    
    randomized.css('background-color', 'red');
});