What would cause a try/catch block to fail exception handling despite execution landing in catch block? - scala

Question

The execution from below code
line 108 try
line 109 {
line 110 columnValCSV = columns_List(fileNumber)(columnNumber)
line 111 }
line 112 catch
line 113 {
line 114 case e: Exception => println(columnValCSV +"OtherLogText")
line 115 }
lands in the catch block as shown in the stack trace.
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException:
10 at Main$.$anonfun$parseSecondDataSource$2(Main.scala:114) at
Main$.$anonfun$parseSecondDataSource$2$adapted(Main.scala:85) at
scala.collection.Iterator.foreach(Iterator.scala:929) at
scala.collection.Iterator.foreach$(Iterator.scala:929) at
scala.collection.AbstractIterator.foreach(Iterator.scala:1417) at
Main$.$anonfun$parseSecondDataSource$1(Main.scala:85) at
Main$.$anonfun$parseSecondDataSource$1$adapted(Main.scala:68) at
scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:59)
at
scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:52)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at Main$.parseSecondDataSource(Main.scala:68) at
Main$.main(Main.scala:147) at Main.main(Main.scala)
However, instead of avoiding throwing an exception as my code is supposed to do, it crashes.

Answer 1

An exception handler can also throw.
scala> try throw null catch { case _: NullPointerException => ??? }
scala.NotImplementedError: an implementation is missing
at scala.Predef$.$qmark$qmark$qmark(Predef.scala:347)
at .liftedTree1$1(<console>:1)
... 28 elided

Answer 2

The actual print statement in the catch block references the same variable I put in the try block. That was the problem