JSFiddle - React, Tailwind, and code Playground

HTML

<div id="listItem"></div>

JavaScript

var mainlist = [
{
    "id":"20",
    "iName":"Молочный коктейль3 ",
    "iCena":"111",
    "iDesc":"111",
    "categorys_id":"1",
    "created_at":"2014-12-13 14:17:25",
    "updated_at":"2014-12-13 14:17:25",
    "categorys":
    {"id":"1","catName":"555","catSort":"2","catDesc":"5555","created_at":"2014-12-11 02:27:01","updated_at":"2014-12-11 07:00:44"}
},
{
    "id":"21",
    "iName":"Немолочный коктейль 2",
    "iCena":"1",
    "iDesc":"111",
    "categorys_id":"4",
    "created_at":"2014-12-13 14:18:31",
    "updated_at":"2014-12-13 15:23:47",
    "categorys":
    {"id":"4","catName":"666","catSort":"1","catDesc":"Lorem i","created_at":"2014-12-11 06:59:15","updated_at":"2014-12-11 06:59:15"}
}
];

for(var i in mainlist) {
    if(mainlist[i].id == 20) {
        res = mainlist[i];
        break;
    }
}

document.getElementById('listItem').innerHTML = res.iName;