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

George Gregorczyk
George Gregorczyk
3,028 Points
Posted by George Gregorczyk
George Gregorczyk
3,028 Points

while loop

I'm having trouble with that question

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 = sum + counter[numbers]
  counter += 1
}

2 Answers

Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

When retrieving an item from an array, put the array name first, and then the index inside the brackets:

//sum = sum + counter[numbers]  <-- instead of this ...
  sum = sum + numbers[counter]  //  do this
Thomas Oliver Bastable
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Thomas Oliver Bastable
Python Development Techdegree Graduate 29,026 Points
Thomas Oliver Bastable
.a{fill-rule:evenodd;}techdegree seal-36
Thomas Oliver Bastable
Python Development Techdegree Graduate 29,026 Points

Your issue lays in the below line

sum = sum + counter[numbers]

You've got the numbers array confused with the counter. It should be the other way around - the below code should work. Hope this helps.

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