[Can't find what's wrong]Iterate Through the Keys of an Object with a for...in Statement

JavaScript
1

Tell us what’s happening:

I can’t find what is wrong in my code. Can someone please help me?

Your code so far


let users = {
  Alan: {
    age: 27,
    online: false
  },
  Jeff: {
    age: 32,
    online: true
  },
  Sarah: {
    age: 48,
    online: false
  },
  Ryan: {
    age: 19,
    online: true
  }
};

function countOnline(obj) {
  // change code below this line
  let count = 0;
  for(let user in users){
    if(user['online'])
      count++;
  }
  return count;
  // change code above this line
}

console.log(countOnline(users));

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0.

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-data-structures/-iterate-through-the-keys-of-an-object-with-a-for---in-statement/

2

the for…in loop gives strings that are the object keys
so user is a string and doesn’t have properties like an object

an other thing you may consider is that you are in a function, and best practice is to use the function parameter

3 
function countOnline(obj) {
  // change code below this line
  let count = 0;
  for(let user in obj){
    if(user == true)
      count++;
  }
  return count;
  // change code above this line
}

I changed my code into this still wrong.

4

try using console.log(user) in your loop to understand what user is

5

I know it’s the names of the users. But how can I judge the value of online to be true.

6

you have an object

let users = {
   Alan: ...
   Jeff: ...
   Sarah: ...
   Ryan: ...
}

the names are the keys of this object, each of this properties has value of an other object

do you remember how to access nested objects?

7

I’ve been using obj.key to access nested array, but why can’t I be admitted on this one…:cry:

function countOnline(obj) {
  // change code below this line
  let count = 0;
  for(let user in obj){
    //console.log(user);
    if(user.online == true)
      count++;
  }
  return count;
  // change code above this line
}
8

Hmm I don’t see why your first technique isn’t correct either…

9

I know the answer!!! :smiling_imp: The answer is to change " user.online" into “obj[user].online” so that we can use the string into the JavaScript syntax.

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