Undefined Value from Function

JavaScript
1

Tell us what’s happening:
I’m confused could someone please tell me what I’m doing wrong? Also please expand on the concept. I want to understand this and I find it confusing. Thank you.

Your code so far


// Setup
var sum = 0;

function addThree() {
sum = sum + 3;
}

// Only change code below this line


// Only change code above this line

addThree();
function addFive(){
sum = sum + 5;
}

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1 Safari/605.1.15.

Challenge: Understanding Undefined Value returned from a Function

Link to the challenge:

2

For starters, your code must be inside the two comments

// Only change code below this line


// Only change code above this line
3

Like JeremyLT said, you must define the function inside the two comments. Also, call the function at the end.