For example, exceptions are unchecked, and lambda expressions are supported. In general, Kotlin is readable, relatively simple to pick-up for beginners and in many ways more modern than Java.

Plans for Kotlin 1.4, ... The compiler converts the lambda to an instance of the class implementing the abstract member function.

Have a look at the function declaration near the top of both panes. The return type in Java precedes the prototype, but in Kotlin it succeeds the prototype, demarcated with a colon as in Pascal.