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

Code challenge for while loop see image > http://postimg.org/image/ini3vgkk7/

can't get through with this code challenge. what have i done wrong here?

while.swift
//code challenge
let numbers = [2,8,1,16,4,3,9]
var sum = 0
var counter = 0

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

}

2 Answers

Paul Brazell
Paul Brazell
14,371 Points

Two things. You need to make it only less than, not less than or equal to. Main thing is that you need to increment the counter after you've added it to the sum. You are basically getting a subscript out of bounds error.

Try this:

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

while counter < numbers.count {

    sum += numbers[counter]
    counter += 1 // Increment this way because increment and decrement operators are going away in Swift 3.0

}

This is sorted and here's my answer.

//code challenge
let numbers = [2,8,1,16,4,3,9]
var sum = 0
var counter = 0
while counter < numbers.count {
    sum += numbers[counter]
    counter++
}

print(sum)