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How do I create an array of tuples in Swift where one of the elements in the tuple is optional?

Take the following code:

var tupleArray: [(firstName: String, middleName: String?)] = []
tupleArray.append(firstName: "Bob", middleName: nil)
tupleArray.append(firstName: "Tom", middleName: "Smith") // causes an error

I need an array of tuples consisting of a name and a middle name, the middle name can be nil or have a value (thus optional). However, with the above create code, the third line gives me an error. What for? How do I get around this?

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3 answers


This could be a compiler error. How in How do I create an array of tuples? , you can define a type alias as a workaround:



typealias NameTuple = (firstName: String, middleName: String?)

var tupleArray: [NameTuple] = []
tupleArray.append( (firstName: "Bob", middleName: nil) )
tupleArray.append( (firstName: "Tom", middleName: "Smith") )
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Another workaround would be to do it Optional<String>.Some

explicitly.



var tupleArray: [(firstName: String, middleName: String?)] = []
tupleArray.append(firstName: "Bob", middleName: nil)
tupleArray.append(firstName: "Tom", middleName: .Some("Smith"))
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Something interesting. This seems to be an error somehow, but we can add using a different syntax using the following method

var pfc : [(prime: Int, count: Int)] = []

pfc.append(prime: 2, count: 2)

pfc += [(prime: 3, count: 4)]

var p = 5
var c = 1

var tuple = (prime: p, count: c)

pfc += [tuple]

for optical variables the following code ( originally provided by Martin R ) passes , it works fine for me

    typealias tupleArray =  (firstName: String, middleName: String?)

    var fun1: [tupleArray] = [tupleArray]()
    fun1.append((firstName: "Bob", middleName: nil))
    fun1.append((firstName: "Tom", middleName: "Smith"))
    println(fun1)
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