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

Posted by Lester Paredes
Lester Paredes
4,543 Points

Why won't the code work on the second challenge question?

I can't figure out why this doesnt work.

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[counter]
  counter += 1
}

1 Answer

Steven Parker
Steven Parker
231,184 Points
Steven Parker
Steven Parker
231,184 Points

Using "<=" for the loop test will cause the loop to run one time too many.
Use a "<" test instead to stop the loop before it tries to use an index too large.