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

Please help! There is a bug, can't see the "Preview", even though they say i should see it. I don't understand.

I don't understand this task! I have done the first part, where i have used the value of "counter" as an index value, but what i don't understand is how a should retrieve it and add it to "sum". And the example below isn't much help either (where does the "newValue" come from suddenly!?) I have tried to figure it out by myself, but it is kinda hard, when i can't use the "Preview"-button, which has disappeared even though i should look at it. There is clearly an simple and obvious answer, but i can't find it and i haven't had much help. So therefore i have decided to write to you guys for some help and advice.

Thank you in advance

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

// Enter your code below
while counter < numbers.count {
      counter += 1


2 Answers

Hi Adam,

There's no bug, unfortunately.

You've accessed numbers[counter] but done nothing with it! You need to += the value held in numbers[counter] into sum within the loop. So just add sum += in front of that line:

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

Make sense?