How to convert an Array to a Tuple?

Question

I have an Array[Any] from Java JPA containing (two in this case, but consider any a small number of) differently-typed things. I would like to represent these as tuples instead.

I have some quick and dirty conversion code, and wondered how it could be improved and perhaps made more generic.

val pair = query.getSingleOrNone // returns Option[Any] (actually a Java array)
pair collect { case array: Array[Any] =>
  (array(0).asInstanceOf[MyClass1], array(1).asInstanceOf[MyClass2]) }

Solution 1

How about this?

val pair = query.getSingleOrNone
pair collect { case Array(x: MyClass1, y: MyClass2, _*) => (x,y) }
// result would be Option[(MyClass1, MyClass2)]

Solution 2

Use map { case Array(f1,f2) => (f1,f2) }.

Here is an example:

Array( "CA:California", "WA:Washington", "OR:Oregon").
  map(s => s.split(":")).
  map { case Array(f1,f2) => (f1,f2)}

Solution 3

My solution is as below:

val loginValues = line.split(",")  // return an Array

val (ip, date, action, username) = (loginValues(0), loginValues(1).toLong, loginValues(2), loginValues(3))

Solution 4

You can use Tuple.fromArray. Works for Scala 3.0.2, haven't checked earlier versions.

scala> val a = Array("a", "b")
val a: Array[String] = Array(a, b)

scala> Tuple.fromArray(a)                                                        
val res1: Tuple = (a,b)

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