Imported From: https://issues.scala-lang.org/browse/SI-3711?orig=1
Reporter: Eugene (euee)

@retronym said:
Array[Int] is precisely the same as int[] in Java. Scala can't doesn't attempt to change the result of Array[T]#toString.

The pretty output on the first line is a nicety of the REPL, but can only work in an expression evaluates to Array.

See:

http://stackoverflow.com/questions/2481149/why-does-array0-1-2-array0-1-2-not-return-the-expected-result
http://stackoverflow.com/questions/3328085/scala-printing-arrays
http://stackoverflow.com/questions/1973397/string-representation-of-objects-as-in-scala-repl/1973591SI-1973591
http://stackoverflow.com/questions/3213368/strange-behaviour-of-the-array-type

And probably more I missed.

Eugene (euee) said:
Thank you!
but is it a compatibility problem?

C:\opt\scala-2.7.7.final\bin>scala.bat
Welcome to Scala version 2.7.7.final (Java HotSpot(TM) Client VM, Java 1.6.0_21).
Type in expressions to have them evaluated.
Type :help for more information.

scala> Array(1,2)
res0: Array[Int] = Array(1, 2)

scala> println(res0.toString())
Array(1, 2)

scala>

@paulp said:
Replying to [comment:3 euee]:

Thank you!
but is it a compatibility problem?

Only if someone was depending on the output of toString. Rather unwise.

In any case, 2.7 is much worse from a consistency standpoint. Extending your example a little:

Welcome to Scala version 2.7.7.final (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_20).
Type in expressions to have them evaluated.
Type :help for more information.

scala> Array(1,2)            
res0: Array[Int] = Array(1, 2)

scala> println(res0.toString())
Array(1, 2)

scala> println(res0)           
[I@36d98810

scala>