CODEWITHSUNDEEP
scalavariablestypes
Michael
Michael

Reputation: 16142

return type of the variable in Scala

How can i see type of the variable in Scala?

I have tried to do this like that:

val x = 10
println(type(x))

or

val x = 'Hello!'
println(x.type)

Bun unfortunately in both of these ways i have an error.

Upvotes: 2

Views: 2603

Answers (1)

timday
timday

Reputation: 24892

Depending what you're trying to do, this might be sufficient

val x=10
println(x.getClass.toString)

However, this breaks down due to type erasue; Scala has more information than Java does and the above only gives you Java's view. There's a thread here with more on this theme; outcome is:

def manOf[T:Manifest](t:T):Manifest[T] = manifest[T]
println(manOf(1))
println(manOf(List(1,2,3)))

gets you

Int
scala.collection.immutable.List[Int]

wheras the .getClass.toString method will only get you an int and a mysterious class scala.collection.immutable.$colon$colon

Of course if you're using the REPL shell it tells you the (scala) type of things anyway:

$ scala
Welcome to Scala version 2.9.2 (OpenJDK 64-Bit Server VM, Java 1.6.0_27).
Type in expressions to have them evaluated.
Type :help for more information.

scala> val x=10
x: Int = 10

Upvotes: 6

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