JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = [
    {
    "id" : 1,
    "name" : "carrot",
    "price" : 0.10,
    "stock" : 12,
    "bgLocation" : "-1px -54px"
    },
    {
    "id" : 2,
    "name" : "fennel",
    "price" : 1.20,
    "stock" : 6,
    "bgLocation" : "-146px -52px"    
    }
]
    
var item = $.extend({}, data[0]);
item.added = 4;

$('body').append(JSON.stringify(data[0]));