Question

Am I right understanding that

• def is evaluated every time it gets accessed

• lazy val is evaluated once it gets accessed

• val is evaluated once it gets into the execution scope?

Answer 1

Yes, though for the 3rd one I would say “when that statement is executed”, because, for example:

def foo() {
    new {
        val a: Any = sys.error("b is " + b)
        val b: Any = sys.error("a is " + a)
    }
}

This gives "b is null". b is never evaluated and its error is never thrown. But it is in scope as soon as control enters the block.