For...in Statement | What's the problem?

JavaScript
1

Hi, all

I have a problem with Iterate Through the Keys of an Object with a for…in Statement | challenge.
First, this is my code :

 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
 // Create var called 'i' to start count online users from 0 
  let i = 0;
 // use for to display all key for any obj come from function argument  
  for (let user in obj) {
// small condition to compare online key with his content 
    if(obj[user]['online'] == true) {
      return i++
    }
  }
  // change code above this line
}

console.log(countOnline(users));

I tried to explain my answer in the comments above and give you some information about how i think of it but, it’s return 0 ? and i don’t know why ??

Thanks for spending your time to help me :blush:

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

A return statement stops function execution and returns whatever the expression to its right evaluates to. That’s what happens inside your for loop right now, the first time it encounters a user who is online.

2 Likes
3

The for in loop is accessed only one time, at the end of the first and only iteration the return statement breaks the function and returns the value of i before the ++ operator changes the value of i.

2 Likes
4

Your for loop should be operating on the i variable and not return (you should be returning after the loop is over instead). You also reference obj[users] which doesn’t exist

Edit: for some reason I missed the obj being referenced as an argument to the function :sweat_smile:

1 Like
5

Hi, @huntinghawk1415
First thanks you to trying help me but, i think you mean normal For and Not for in loop for Object ??

how can i put i var to inside for loop (that’s right in normal for loop but, here i can’t do this)

thanks again and it’ll greet help if you can write a bit more explanation

6

First thank you for your comment but, i don’t understand how can return stops function ?

i think it should return new value after increment 1

maybe i’m missing something ?

7

sorry but, if someone can rewrite my function in the right way and explain what is happen ?

it’s very important for my because i think i really understand for in and object but i feeling i lost something or missing something important

thanks again

8

Sure thing!

So, to clarify, I said your for loop (i.e. your for...in... loop) should be operating on the i variable, not to use it as a traditional for loop i. For example (minor spoilers ahead if you still want to try it on your own without any structural guidance):

const obj = {a: 'hey'}

function myFunc() {
  let i = 0

  for (let key in obj) {
    //increment the i variable, but don't return in here.
    //returning in here will return the entire function, not "break" the for loop
  }

  //return the i variable when you've achieved what needs to happen in the for loop
}
1 Like
9

you are right, you are doing really well, it is just that the return statement will stop the function and return the value, so if you put it inside a loop, the loop doesn’t do what you want. and if you use i++, that is enough to change the value of i, there it is not necessary to use return there

the return statement is necessary, just somewhere else

1 Like
10

@huntinghawk1415 @ILM
OH, Finally!! i understand what was happened here :sweat_smile::sweat_smile:
I thought i’m very stupid :upside_down_face:

well, it’s really greet help and it’ll help me later to understand what really return sequence can do !!
So, THANK YOU AGAIN and sorry if you tried with my :heartbeat:

Also, thanks for everyone :blush:

1 Like
11

Very stupid !? Not for sure! The aha moment is sign of intelligence :wink: You kept reading, trying and asking according to the information everyone was giving you. Now you have understanding of for…in iterator, i++ operator and return statement. What an adventure.

1 Like