JSFiddle - React, Tailwind, and code Playground

by taylorRichie

HTML

<div id="r"></div>

JavaScript

var jsonOld = '[{"id":"70","type":"ab","dateadded":"12345678"},{"id":"85","type":"ab","dateadded":"87654321"}]',
    jsonNew = '[{"id":"12341234234","created_time":"12345678"},{"id":"567856785678","created_time":"87654321"}]';

var mainArr = JSON.parse(jsonOld),
    newArr = JSON.parse(jsonNew);

for (var i = 0, il = newArr.length; i < il; i++) {
    newArr[i].type = 'ab';
    newArr[i].dateadded = newArr[i].created_time;
    delete newArr[i].created_time;
}

mainArr = mainArr.concat(newArr);
mainArr.sort(function(a, b) { return a.dateadded - b.dateadded; });
             
document.getElementById('r').innerHTML = JSON.stringify(mainArr);