For loops with optional arrays, is there a better, less wordy way?

[eblu (eblu's full name)]

I have a bunch of optional arrays in my current project and to traverse the array it's become very wordy:

if let a = optionalArray{
for anItem in a{
// doo stuff here.
}
}

because :

for anItem in optionalArray?{
// stuff
}

causes an error.
am I missing something? is this intended behavior? who can I make suggestions to in that case?

thnx,
-td

[mrc (Marco Capano)]

I think this is intended. You could use forEach instead, with optional chaining like this:

optionalArray?.forEach { /*do stuff here*/}

Or, if you want to use the classic for -> in approach you could do like this:

for element in optionalArray ?? [] {
      /* do stuff here */
}

Both solutions do nothing if the array is nil, which I think is the behavior you're looking for.

-mrc

[eblu (eblu's full name)]

thanks, I'll give that a shot.

[Tino]

This pops up from time to time:

for with optional collection?

To me it would seem more logical as "for x in array? { }" — to parallel "for case let x? in array { }"

···

On Fri, Feb 10, 2017 at 1:03 PM, Rick Mann via swift-users < swift-users@swift.org> wrote: I love the idea of for in? (Or even for? In). You should pitch that to evolution. Sent from my iPhone On Feb 10, 2017, at 07:04, Tino Heth <2th@gmx.de> wrote: Is there any concise way to write the following? if let collection = someOptionalCollection {    for item in collection …

for in? optionalCollection {

This one started over at swift-users, with a question on how to deal with looping over containers that may be nil. Imho the beauty of the feature is that it's simple enough to be explained in the subject line, but here is the "long" story: let test: [Int]? = nil // this is possible now if let test = test {   for i in test {     print(i)   } } // how it could be written with a modified keyword for i in? test {   print(i) } I've been thinking "in?" had been brought up long ago, but as…

... and there are more threads with possible "workarounds".

@mrc

for element in optionalArray ??

Is what I do most of the time as well -- although I alway feel bad because I never checked if this actually creates an empty array with the associated overhead compared to if let (but in most cases, overhead doesn't matter anyways...)