JSFiddle - React, Tailwind, and code Playground

JavaScript

function myStringify(item)
{
var str, i;
str = '';
for (i in item)
    {
    if (typeof item[i] === 'object')
        {
        str += myStringify(item[i]);
        continue;
        }
    str += "<br>" + i + " = " + item[i];
    }
return str;
}

var x, item;
item = {id: 123, name: "kamenolom", postaveni: {kameni: 0, zelezo: 0, drevo: 10},  vyrabi: {kameni: 30, zelezo: 0, drevo: 0}};
document.write(myStringify(item))