Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

Posted by vcky war
vcky war
Courses Plus Student 414 Points

collection and control

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.

while.swift 
let numbers = [2,8,1,16,4,3,9]
var sum = 0
var index = 0

// Enter your code below

while index += numbers  {
print([index])
index++
}

1 Answer

Nathan Tallack
Nathan Tallack
22,160 Points
Nathan Tallack
Nathan Tallack
22,160 Points

So what we are trying to do here in task 1 is set up a while loop. The way the english of the task reads helps you understand how. They say "while counter is less than the length of the array" and hint you can use the count method on the array to calculate that.

The second task tells us to add each array item to the sum variable. Again it hints we can use the counter as the index number for the array item.

So then your code would look something like this.

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

// Enter your code below

while counter < numbers.count {  // This is the first task.
    sum += numbers[counter]  // This is the second task.
    counter++
}
vcky war
vcky war
Courses Plus Student 414 Points

thnku sir