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### Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today. # How do you add integers of arrays together?

Here is the question:

Now that we have the while loop set up, it's time to compute the sum! Using the value of counter as an index value, retrieve each value from the array and add it to the value of sum.

For example: sum = sum + newValue. Or you could use the compound addition operator sum += newValue where newValue is the value retrieved from the array.

Here is the code I have typed. Please can you let me know what I've done wrong?

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

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

Thanks

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

while counter < numbers.count {
sum += numbers[]
counter += 1
}
``` You can't just add all the elements of an array together like that, though it'd be cool. Using a `for` loop instead of a `while` loop with a counter would be right up this question's alley Ohh lol that's what I get for just answering without looking at the question :P In that case, your code looks mostly good, but to get a value out of an array, you need to provide a number to its subscript. For example `numbers` gets the first value in the `numbers` array. What variable in your code starts at `0` and increases by `1` for as many objects as there are in the `numbers` array? It looks like you forgot to use the index value for numbers inside the while loop. As you go through the loop counter will start as zero and end up with the number or items in "numbers[]" minus one. In this case counter will go from zero to six.

You can test that by putting a print(counter) inside the loop. Try it just before the sum is added.

Once you have done that change the print to be "print(numbers[counter])" and you can see each element in the array. You should be able to see what to do next to fix that sum addition statement.

Happy coding!

PS. I know you got your answer a few hours ago but I still wanted to give you some troubleshooting tips. Put some print statements in a loop to see what it is doing.