val x = new Array[Integer](3) //type inferred for x
x(0) = 1
x(1) = 2
x(2) = 3
for (y <- x if y > 2)
println(y)
The idiomatic way to do this is:
val x = Array(1, 2, 3)
That infers the type and sets values in one shot, with fewer characters. Also, using Integer (that's the java.lang.Integer) has been deprecated since 2.8.1 I believe. `Int` is preferred unless you really mean to use `Integer` (e.g. you're using a native Java library).
C:\Users\bert>scala
Welcome to Scala version 2.9.2 (Java HotSpot(TM) Client VM, Java 1.7.0_06).
Type in expressions to have them evaluated.
Type :help for more information.
scala> val x = Array(1, 2, 3)
x: Array[Int] = Array(1, 2, 3)
scala>
You can see that scala infers the type right (Array[Int]).
Even, I find this strange and I may be wrong. With your definition, when I use the for construct, I see this:
scala> for (y<-x if x > 2)
| println(y)
<console>:9: error: value > is not a member of Array[Int]
for (y<-x if x > 2)
^
As you suggested, there may be a idiomatically better way to get implicit inference and also use the filters. I would be glad if some one corrects me on that.
Edit: Yeah, I see the silly error I made. I'll better get some sleep. I will leave this comment intact, for the responses to make sense.
Get some sleep, then spend another week playing with Scala and its REPL. It's a terrific tool to learn. If you like Eclipse, install the Scala IDE and the Scala Worksheet. It's rough around the edges, but it's even better than the REPL.
Yes, I have been using the Scala IDE and Scala worksheet for my initial learning. As you said, it is great and more friendly than the REPL itself. It reminds me of Python Notebook in terms of being able to get good feedback and recursively edit.
