Convert JavaScript object to x-www-form-urlencoded format

JSON_to_URLEncoded.js

function JSON_to_URLEncoded(element,key,list){
  var list = list || [];
  if(typeof(element)=='object'){
    for (var idx in element)
      JSON_to_URLEncoded(element[idx],key?key+'['+idx+']':idx,list);
  } else {
    list.push(key+'='+encodeURIComponent(element));
  }
  return list.join('&');
}

JSON_to_URLEncoded_TEST.js

var data = {
  'users' : [
    {
      "id": 100,
      "name": "Stefano"
    },
    {
      "id": 200,
      "name": "Lucia"
    },
    {
      "id": 300,
      "name": "Franco"
    },
  ],  
  'time' : +new Date
};

console.log(
  JSON_to_URLEncoded(data)
);

/*
Output:

users[0][id]=100&users[0][name]=Stefano&users[1][id]=200&users[1][name]=Lucia&users[2][id]=300&users[2][name]=Franco&time=1405014230183

*/

import qs from 'querystring';
qs.stringify({ 'key': 'value' })

this worked really well for me.

The gist was from 7 years ago... hopefully things have improved since then sweat_smile
not as much as you'd think :-)