var parent = {
  one: 1,
  two: 2,
  arr: [1, 2],
  obj: { one: 1, two: 2 },
};

function copy(o) {
  var out = Array.isArray(o) ? [] : {};
  for (var key in o) {
    var v = o[key];
    out[key] = typeof v === "object" ? copy(v) : v;
  }
  return out;
}