Try … catch … finally return value

Question

I found that it\'s a shame that I can\'t return a return value from a such simple construction as try ... catch ... finally

 def foo: String = {
            


        

Answer 1

This is happening because in Scala unlike Java, try-catch are expressions. In your code, try block returns a String and your catch block return type is Unit (as you are just printing and returning nothing).

The type-inference hence takes the return type T such that T >: Unit and T >: String. Hence T is of type Any. And because you have declared foo as def foo: String. The compiler throws an error as it was expecting String but found Any.

What you can do is to return a default value under you catch block:

try{
  in.readLine
}
catch {
  case e: IOException => {
             e.printStackTrace()
             "error string"
         }
}
 finally{
     in.close
 }