JSFiddle - React, Tailwind, and code Playground

HTML

Product 1: <button id="product1">Add one</button>
<br>
Product 2: <button id="product2">Add one</button>
    
<div></div>

JavaScript

var cart = [], count = {};

$(document).ready(function () {

    $('button').on('click', function () {
        var pid = $(this).attr('id');

        cart.push({
            id: pid,
            qty: 1
        });
        
        count[pid] = (count[pid] || 0) + 1;
        
        console.log(count);
    });
});