JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/ui-lightness/jquery-ui.css">

JavaScript

var obj = {
   param1: 'something',
   param2: 'somethingelse',
   param3: 'another'
}

obj['param4'] = 'yetanother';

var str = '';

for( var name in obj ) {
    str += (name + '=' + obj[name] + '&');
}

str = str.slice(0,-1);

alert( str );