Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift 2.0 Collections and Control Flow Control Flow With Loops Working with Loops

Posted by vetahccsob
vetahccsob
7,345 Points

Challenge 2 of 2

Hi, I can't figure out challenge 2 to save my life.

Challenge Task 2 of 2

Now that we have the while loop set up, it's time to compute the sum! Using the value of counter as an index value, retrieve each value from the array and add it to the value of sum.

For example: sum = sum + newValue. Or you could use the compound addition operator sum += newValue where newValue is the value retrieved from the array.

Can someone help me please? I have checked the forums and i can't seem to figure out the explinations. Today is one of those days! :)

Thanks in advance!

while.swift 
let numbers = [2,8,1,16,4,3,9]
var sum = 0
var counter = 0

// Enter your code below

while counter < numbers.count {
print(numbers)
counter++
}

1 Answer

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Derrik,

So, we want to go through the array, and add each number to the sum. That's numbers[0] + numbers[1] + numbers[2] ... etc. We just so happen to have a variable, counter, that is going to go through each of those numbers. All you have to do is add numbers[counter] to the sum variable each time.

while.swift 
while counter < numbers.count {
    sum += numbers[counter]
    counter++
}

Make sense?

Cheers :beers:

-Greg