val and object inside a scala class?

Question

What is the difference between declaring a field as val, lazy val and object inside a scala class, as in the following snippet:

<

Answer 1

I suppose one difference is that a1 will be of one subtype of A while a2 will be of another subtype of A namely a2.type.

scala> class A
defined class A

scala> val a1 = new A {def foo = 1}
a1: A{def foo: Int} = $anon$1@a9db0e2

scala> object a2 extends A {def foo = 1}
defined module a2

scala> a1
res0: A{def foo: Int} = $anon$1@a9db0e2

scala> a2
res1: a2.type = a2$@5b25d568

scala>