JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="product[1]">
<input type="checkbox" name="product[2]" checked>

JavaScript

var data = {product: []};
$('input').each(function(){
    data.product[$(this).attr('name').match(/product\[([\d]*)\]/)[1]] = $(this).prop('checked');
})
console.log(data);