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iOS Swift Collections and Control Flow Introduction to Collections Working With Arrays

Posted by Cristobal Heiss
Cristobal Heiss
5,437 Points

Hi, I'm dealing with the Challenge Yask 4 of 4 in Swift 3 Collections and Control Flow.

Hi, I'm dealing with the Challenge Yask 4 of 4 in Swift 3 Collections and Control Flow. The first problem is I don't know why when I add 80 to the array using concatenation (arrayOfInts + [80]) the 80 won't remain in my array. The second problem is that after I remove the 6th element (arrayOfInts.remove(at: 5)) I try to create the constant with the discarded value (let discardedValue = arrayOfInts[5]) and it won't work (and the same did work before, in challenge 3 of 4). I have no idea what's going on.

Thanks in advance

array.swift 
// Enter your code below

var arrayOfInts: [Int] = [22,24,28,52,66,72]

arrayOfInts.append(78)

arrayOfInts + [80]

arrayOfInts.remove(at: 4)

let value = arrayOfInts[4]

arrayOfInts.remove(at: 5)

let discardedValue = arrayOfInts[5]

3 Answers

carriebarnett
carriebarnett
16,732 Points
carriebarnett
carriebarnett
16,732 Points

On this line: arrayOfInts + [80]

Instead of using just the "+", try "+=". That should fix both problems for you.

Cristobal Heiss
Cristobal Heiss
5,437 Points

Thanks carriebarnett, that was it!

Jeff McDivitt
Jeff McDivitt
23,970 Points
Jeff McDivitt
Jeff McDivitt
23,970 Points

Here is the correct answer to this one. As for your question, how do you know that the 80 is not staying on your array?

var arrayOfInts = [1,2,3,4,5,6]

arrayOfInts.append(7)

arrayOfInts += [8]

let value = arrayOfInts[4]

let discardedValue = arrayOfInts.remove(at: 5)
Cristobal Heiss
Cristobal Heiss
5,437 Points

The problem was solved, thanks for your time

Cristobal Heiss
Cristobal Heiss
5,437 Points
Cristobal Heiss
Cristobal Heiss
5,437 Points

Hi Jeff, thank you very much for the answer. I know it's not staying because I do the exercises in Xcode and after typing the following code:

var arrayOfInts: [Int] = [22,24,28,52,66,72]

arrayOfInts.append(78)

arrayOfInts + [80]

arrayOfInts.remove(at: 4)

let valorem = arrayOfInts[4]

arrayOfInts

When I write arrayOfInts to print the elements it displays all of them but the "80". Not sure why really