Iterate through keys of an object using for..in statement (freecodecamp notes)

In a JSON object we have key and value pairs.

An example would be something like this

var object = { key1 : { name : 'xxxxxx', value : '100.0' }, key2 : { name : 'yyyyyyy', value : '200.0' }, key3 : { name : 'zzzzzz', value : '500.0' }, 

Exercise

We have defined a function named 'countOnline(userObj)' , using a for ..in statement within this function loop through the users object passed into the function and return the number of users whose online property is set to 'True' . Example of users object that will be passed to countOnline is shown below

{ Alan:{ online:false }, Jeff:{ online:true }, Sarah:{ online:false } } 

Attempts

 //Attempt 1 function countOnline(userObj){ let count; for (let user in users) { if (user.online==true) count ++ } } //Attempt 2 function countOnline(usersObj) { // Only change code below this line let count=0; for (let user in usersObj){ if(usersObj[user].online==true){ count++ } } return count // Only change code above this line } console.log(countOnline(users)); 

Correct answer?? Attempt 2

1.Attempt 1 did not work because when we do user.online, user will only have the string (ie.Alan, Sarah etc)

2.Attempt 2 worked because we correctly used the syntax to get the online property of each user inside usersObj

Try this out in freecodecamp https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-data-structures/iterate-through-the-keys-of-an-object-with-a-for---in-statement