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

Jonathan Lee
Jonathan Lee
1,565 Points
Posted by Jonathan Lee
Jonathan Lee
1,565 Points

How do I add all the values of the array to the sum?

sum = sum + numbers[counter] // out of bounds sum = sum + numbers[1...6] // unknown error help please

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])
  counter++

 }
Jonathan Lee
Jonathan Lee
1,565 Points
Jonathan Lee
Jonathan Lee
1,565 Points

I believe the error was due to the fact that I inserted sum += numbers[counter] after counter ++ instead of before.

while counter < numbers[counter]
counter++
sum += numbers[counter]

This was the code that I had an error with.

Anjali Pasupathy
Anjali Pasupathy
28,883 Points
Anjali Pasupathy
Anjali Pasupathy
28,883 Points

You're correct. In the last run of the loop, counter is increased to an index higher than the last index in numbers. That's why you get the array out of bounds error.

1 Answer

Anjali Pasupathy
Anjali Pasupathy
28,883 Points
Anjali Pasupathy
Anjali Pasupathy
28,883 Points

sum = sum + numbers[counter] shouldn't be out of bounds if you're putting that line of code inside the while loop. I copied and pasted your code with "sum = sum + numbers[counter]" replacing "print(numbers[counter])" because you don't need to print anything for this challenge, and it passed.

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 + numbers[counter]
  counter++

 }