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

Posted by Jochen Bams
Jochen Bams
799 Points

Challenge Task 2 of 2

I'm unable to finish challenge task 2 of 2. Where can I find the answer so that I can self evaluate, learn what I did wrong and continue the course? Really frustrating that I'm unable to look up the answer after 15 failed tries with different lines of code.

Anthony Lafont
Anthony Lafont
17,075 Points
Anthony Lafont
Anthony Lafont
17,075 Points

Hi Jochen,

The best way is to post your code. We can't do anything for you if we don't know what you're doing wrong!

3 Answers

Anthony Lafont
Anthony Lafont
17,075 Points
Anthony Lafont
Anthony Lafont
17,075 Points

No problem Jochen ;)

In your first proposition, you were very close to the answer!

The problem was just because of your condition in the while loop.

You're telling the compiler that it has to loop while the counter is inferior OR EQUAL to the number.count.

By doing this that way, the last iteration of the loop will be the following:

while counter <= numbers.count {  // 9nth time iteration
sum += numbers[8] // Here is the problem, there is no 9th element in the array. So the compiler is returning an error
counter += 1 
}

So you only have to change the condition to be right

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

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

Anthony

Jochen Bams
Jochen Bams
799 Points

Thanks Anthony, that makes sense. I have a long way to go ;-)

Jochen Bams
Jochen Bams
799 Points
Jochen Bams
Jochen Bams
799 Points

Thanks for the quick reply Anthony.

I'm trying to finish the challenge currently as follows:

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

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

or by doing this:

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

while counter <= numbers.count { 
sum = sum + newValue 
counter += 1 
}
Jochen Bams
Jochen Bams
799 Points
Jochen Bams
Jochen Bams
799 Points

Sorry had to edit it a couple of times to match the syntaxes of the Forum, so it would show right. It's my first time posting stuff on the community here so trying to get the hang of it all :)