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

Kristopher Wood
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Kristopher Wood
iOS Development Techdegree Student 5,552 Points
Posted by Kristopher Wood
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Kristopher Wood
iOS Development Techdegree Student 5,552 Points

Lost on how to retrieve the value from the array

Would appreciate help on this one. Not sure how to finish this off and retrieve the value from the array. Thanks

loops.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) + \(numbers)")
  counter += 1
  }

  repeat {
    print ("sum = sum + numbers)
      counter += 1
      } while counter < 1

2 Answers

Alex Koumparos
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Alex Koumparos
Python Development Techdegree Student 36,887 Points
Alex Koumparos
.a{fill-rule:evenodd;}techdegree
Alex Koumparos
Python Development Techdegree Student 36,887 Points

Hi Kristopher,

First, you don't need any of the repeat block, so let's just delete that to get your plain while loop:

while counter < numbers.count {
  print("\(numbers) + \(numbers)")
  counter += 1
}

Now, we need to replace the print statement you have right now with code to perform the actions from the challenge:

1: "Using the value of counter as an index value, retrieve each value from the array"

So this means we need to access the values in numbers with counter. Accessing the values in an array was handled back in Introduction to Collections. Or if you want a text-based refresher on accessing arrays, you can look at Apple's (very readable) Swift Language Guide.

2: "add it to the value of sum"

Once we have the value from the array we just add that to the existing value. The challenge gives examples of syntax for doing this, either:

sum = sum + newValue

or

sum += newValue

Where newValue is the value you got from the array.

Hope this helps. If you're still stuck after revisiting the Introduction to Collections video and/or reading Apple's guide to arrays, let me know which bit you don't get and I'll give you some more pointers.

Cheers

Alex