Unable to assign value to a var inside try in Scala

Question

In my program, I have:

val f = Source.fromURL(url)
var lineList
try lineList = f.getLines.toList finally f.close()

I get compilation error:

Error:(13, 1) '=' expected but ';' found. try lineList = f.getLines.toList finally f.close()

What mistake am I making?In fact I am doing what error message asks me to do.

when you declare a variable it should be explicitly initialized. Just initialize it like var lineList = _ — Alex Evseenko, Apr 17 '18 at 13:16
Why not doing `val lineList: Seq[String] = { try { f.getLines.toList } finally f.close() }` ? — ccheneson, Apr 17 '18 at 15:32

Saskia · Answer 1 · 2018-04-18T08:41:06.783

1

Since you're not assigning something to lineList it needs a type definition, because the compiler cannot infer the type.

var lineList: List[String]

and if your not declaring an abstract class you need to assign it something, e.g. with the wildcard operator _

var lineList: List[String] = _

edited Apr 18 '18 at 08:41

answered Apr 17 '18 at 13:27

Saskia

But doesn't this means we are creating a list object,even though we won't be using it as lineList would be assigned to a another object. – Mandroid Apr 17 '18 at 13:35
@Mandroid no you aren't creating any object, just declaring the variable. You need to specify what type the variable should be. – puhlen Apr 17 '18 at 13:40
In Scasti I had to assign it something. But that's probably due to how Scasti is set up. – Saskia Apr 18 '18 at 06:40

pramesh · Answer 2 · 2018-04-17T15:43:39.937

0

In scala, you cannot just name a variable like in java. Variable needs to be initialized.

If you want to create a variable without initialization you need to specify the type:

var a = _ (doesn t work)

var a: Int = _ (works)

It has a good explanation

edited Apr 17 '18 at 15:43

answered Apr 17 '18 at 15:38

pramesh

2 Answers2