Scala - Exception Handling

       Scala's exceptions works like exceptions in many other languages like Java. Instead of returning a value in the normal way, a method can terminate by throwing an exception. However, Scala doesn't actually have checked exceptions.

       To handle exceptions use a try{...}catch{...} block like in Java except that the catch block uses matching to identify and handle the exceptions.

Throwing exceptions:

 

       Throwing an exception looks the same as in Java.create an exception object and then throw it with the throw keyword:

             throw new IllegalArgumentException

Catching exceptions:

 

     Scala allows to try/catch any exception in a single block and then perform pattern matching against it using case blocks as shown below:

import java.io.FileReader

import java.io.FileNotFoundException

import java.io.IOException

object Test {

def main(args: Array[String]) {

try {

val f = new FileReader("input.txt")

} catch {

case ex: FileNotFoundException =>>{

println("Missing file exception")

}

case ex: IOException => {

println("IO Exception")

}

}

}

}

The behavior of this try-catch expression is the same as in other languages with exceptions. The body is executed, and if it throws an exception, each catch clause is tried in turn