Global Variable in Scala

Question

I am trying to use global variable in Scala. to be accessible in the whole program .

val numMax: Int = 300 

object Foo {.. }
case class Costumer { .. }
case class Client { .. }
object main {
var lst = List[Client]
// I would like to use Client as an object .

}

I got this error :

error: missing arguments for method apply in object List; follow this method with `_' if you want to treat it as a partially applied function var lst = List[A]

How can I deal with Global Variables in Scala to be accessible in the main program . Should I use class or case class in this case ?

With your code comment, it's not entirely clear what you're trying to accomplish. Do you want a globally accessible, mutable list of Client objects? Or do you want to have a single globally accessible Client instance that you want to put in a list? — Aaron Novstrup

Vidya Vidya · Accepted Answer · 2013-11-08T22:28:05

This isn't a global variable thing. Rather, you want to say this:

val lst = List(client1, client2)

However, I disagree somewhat with the other answers. Scala isn't just a functional language. It is both functional (maybe not as purely as it should be if you ask the Clojure fans) and object-oriented. Therefore, your OO expertise translates perfectly.

There is nothing wrong with global variables per se. The concern is mutability. Prefer val to var as I did. Also, you need to use object for singletons rather than the static paradigm you might be used to from Java.

Global Variable in Scala

2 Answers