const proto = { inherited: 'nope' };
const obj = Object.create(proto);
obj.b = 2;
obj[1] = 'one';
obj.a = 1;
Object.defineProperty(obj, 'hidden', { value: 'secret', enumerable: false });
obj[Symbol('sym')] = 'symbolValue';
console.log(
  Object.keys(obj).join(','),
  Object.values(obj).join(','),
  Object.entries(obj).length
);