I was pretty exclusively a Java developer for twelve years before making the switch to Scala. Yes, it was difficult to learn some of the syntactical differences, but now that I have I don't want to turn back. No, this is not a baited question to get a flame-war going, but an honest attempt to get some real feedback by those that believe Scala is more difficult than Java.

Let me lay some ground-rules before we get this discussion going though. First, complex topics in Scala are complex, there's no debate there, but that doesn't make Scala more difficult than Java, there are just more possibilities to what you can accomplish. I say that the argument cannot be made that Scala is more complex if there is not a side-by-side comparison to Java code that is much simpler to understand. This means we have to leave the advanced concepts of implicit conversions, multiple inheritance, and so much more that Scala can do, but are features that bring it beyond the capabilities of Java. Yes, of course you can make an argument that in switching to a language like Scala you will eventually run into these scenarios, but I am speaking purely of the introductory programmer and the "difficulties" between Scala's syntax versus Java's.

Now, can someone give me a scenario of code in Java that would be more complicated to understand in Scala?