Use a function to find common elements in two sequences in Swift

Question

I\'m trying to complete the exercise on page 46 of Apple\'s new book \"The Swift Programming Language\". It gives the following code:

func anyCommonElements         


        

Answer 1

I had compiler errors with the above two solutions, I am running the guide from the iBook in the Xcode 6.01 playground. I had consistent compiler complaints about array declarations I found here so I am assuming the posters may be using an earlier version of swift. If I'm wrong, it would be great to know.

For array declarations, I have found that

    var thingList : [ThingType] = []

has worked consistently, so I tended to go with that, forsaking

    var thing[],thing[]()  // gave compiler errors/warnings

My environment never was able to resolve a thing called T.GeneratorType[.Element]

The solution I came up for this experiment is

---

func anyCommonElements 
                    (lhs: T, rhs: U)
-> [T.Generator.Element]
{
    var  returnValue: [T.Generator.Element] = []
    for lhsItem in lhs {
        for rhsItem in rhs {
           if lhsItem == rhsItem {
              returnValue.append(lhsItem)
           }
        }
    }
    return returnValue
}

let commonNumberList = anyCommonElements([1, 2, 3,4,5,6,7,8], [2,3,9,14,8,21])
println("common Numbers = \(commonNumberList)")

let commonStringList = anyCommonElements(["a","b","c"],["d","e","f","c","b"])
println("common Strings = \(commonStringList)")

---

The tutorial text really did not properly prepare me at all to actually solve the experiments without a lot of additional reading. Thanks to everyone here for contributing their solutions, it has really helped me get a great introduction to Swift.