What happens to the 'online' property when using for..in?

Tell us what’s happening:
I understand how to access the online property through bracket notation, but I am confused as to why dot notation does not work.

I think that when using:
for( let user in users){

The program individually goes through each ‘user’ in users, and they all retain their properties, but when I console.log(user) only the name prints, and not the other properties; where do they go? How can I access them if I wanted to use dot notation?

For example: users.Alan.online vs for(let user in users){user.online}, where user = Alan and doesn’t seem to carry over the ‘.online’ property.

Your code so far

function countOnline(usersObj) {
// Only change code below this line
let count = 0;
for(let user in usersObj){
  if(usersObj[user].online == true){
  //if(user.online == true){count++;}
return count;
// Only change code above this line

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36.

Challenge: Iterate Through the Keys of an Object with a for…in Statement

Link to the challenge:

user is a variable, which is why we need to use bracket notation.
usersObj.user.online would only work if we had an object that looked like

const usersObj = {
    user: {
        online: true

It will not work for something like

const usersObj = {
    bob: {
        online: true
   mary: {
        online: false