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 Collections and Control Flow Control Flow With Loops Working With Loops

Walker Kinne
Walker Kinne
902 Points

Sum

Just curious why this code would fail?

If I pull into a playground I am able to get the sum perfectly

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

// Enter your code below

while counter < numbers.count{
sum += numbers[index]
counter += 1

}

3 Answers

andren
andren
28,558 Points

The issue is that in this line:

sum += numbers[index]

You refer to a variable called index which does not exist. I'm assuming you meant to type counter instead. If you fix that typo then your code will work fine.

If you use counter instead of index it should pass! Index is not defined in your code!

Walker Kinne
Walker Kinne
902 Points

Thanks for the help! It just clicked!