FAQ: Code Challenges: JavaScript Fundamentals - numImaginaryFriends()


#1

This community-built FAQ covers the “numImaginaryFriends()” exercise from the lesson “Code Challenges: JavaScript Fundamentals”.

Paths and Courses
This exercise can be found in the following Codecademy content:

Web Development

FAQs on the exercise numImaginaryFriends()

Join the Discussion. Help a fellow learner on their journey.

Ask or answer a question about this exercise by clicking reply (reply) below!

Agree with a comment or answer? Like (like) to up-vote the contribution!

Need broader help or resources? Head here.

Looking for motivation to keep learning? Join our wider discussions.

Learn more about how to use this guide.

Found a bug? Report it!

Have a question about your account or billing? Reach out to our customer support team!

None of the above? Find out where to ask other questions here!


#2

Hello. Why does 33 percent need to be written as 0.33 and not 33% ?


#3

0.33 is a literal which can be used directly in calculations. 33% is an abstract which would need to be parsed and interpreted before it can be evaluated. It would have to be written in string form else the JS interpreter will see it as a number followed by the modulo operator and missing an operand so would raise an error.

33 % 10 === 3

If we wish to output to the display, then,

pct = 0.33;
`${pct * 100}% of voters were undecided.`

Note that % is string character.


#5

Why is

const numImaginaryFriends = totalFriends => Math.round(totalFriends * .33);

correct while

const numImaginaryFriends = totalFriends => { Math.round(totalFriends * .33); }

throws an error?


#6

It’s the curly braces. When using a block like that, there is no implicit return. It must be explicit.

{
    return ...;
};

#7

Ah, OK. Thanks for the quick reply @mtf.


#8

Hi,
Can someone explain to me why I can’t write (1/3) instead of .33?

const numImaginaryFriends = totalFriends => Math.round(totalFriends * (1/3))

I end up with an error saying:

Your function should return a whole number ie 1.3 should round down to 1 while 4.9 should round up to 5


#9
 > totalFriends = 8
=> 8
> Math.round(totalFriends * (1/3))
=> 3
 > totalFriends = 7
=> 7
> Math.round(totalFriends * (1/3))
=> 2

It’s not a problem for JS, but may be a problem with the answer the SCT is seeing. Check the instructions and be sure to follow them to the letter.