I don't understand "Basic Data Structures: Iterate Through the Keys of an Object with a for...in Statement"

JavaScript
#1

Tell us what’s happening:
I have no idea what to do in this challenge.

Your code so far


function countOnline(usersObj) {
// Only change code below this line
for (let user in usersObj) {
if (usersObj[user] === true) {
console.log(usersObj++);
return usersObj += 1;
} else {
  console.log(usersObj += 0);
  return usersObj += 0;
}

}

// Only change code above this line
}

console.log(countOnline({ Alan: { online: false }, Jeff: { online: true }, Sarah: { online: false } }));

Your browser information:

User Agent is: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0.

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

Link to the challenge:

#2

The goal is to return how many users inside the usersObj have the online property set to true. Does this sound more clear? How do you understand the task?

1 Like
#3

My code is wrong, how do I fix it.

function countOnline(usersObj) {
  // Only change code below this line
for (let user in usersObj) {
  if (user.online === true) {
  
   usersObj += 1;
  } else if (user.online === false) {
 
  usersObj += 0;
  } else {
return undefined;
  }
}

  // Only change code above this line
}

console.log(countOnline({ Alan: { online: false }, Jeff: { online: true }, Sarah: { online: false } }));
#4

Your first entry which used usersObj[user] in the for-in loop was close but you’re not drilling down deep enough. The question is how do you get the ‘online’ boolean value.

Try this function to console what usersObj[user] returns. If it’s not returning a true or false value then you have to access the property in that object that has a true/false value. How do you do that with objects?

function countOnline(usersObj) {
  for (let user in usersObj) {
    console.log(usersObj[user] ) 
  }
}
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#5

When having this in the console

usersObj[user].online

the results shows

false
true
false
undefined

#6

Exactly. So those are the values you need to check in your for-in loop. If it’s true then the person is ‘online’. The goal is to find out how many users are ‘online’.

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#7

How do I count how many are online?

This is what I tried:

function countOnline(usersObj) {
  // Only change code below this line
    for (let user in usersObj) {
    if (usersObj[user].online === true) {
   return usersObj += 1;
    } else {
     return usersObj += 0;
    }
  }

  // Only change code above this line
}

console.log(countOnline({ Alan: { online: false }, Jeff: { online: true }, Sarah: { online: false } }));
#8

two things - is usersObj what you are using to store the number of online users?
and a return statement when executed will stop the function and return a value

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#9

I don’t know what else to have.

#10

do you understand the goal of this function?

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#11

Yes, it’s to count how many is online.

#12

how do you count something?

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#13

I did += it’s how you count I think.

With a loop, it needs to repeat and count all.

#14

and to what do you add the number?

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#15

I would think countOnline.

I added it to usersObj, because I think it goes then to countOnline.

#16

are you sure? remember that countOnline is a function

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#17

I don’t know how else I’m suppose to add the online ones.

I have tried many things, nothing works.

#18

how would you do that manually? would you keep track overwriting the object you are analizing?

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#19

I don’t have anywhere else to add the numbers. They only give me user, usersObj and online

#20

yes, that’s the starting point, and you need to write the logic to reach the end goal, including any new thing you need

1 Like