Java terminology for differentiating runtime type from compile-time type

Question

In Java, an Object can have a runtime type (which is what it was created as) and a casted type (the type you have casted it to be).

I\'m wondering what

Answer 1

The terminology you are looking for is the Apparent Type and the Actual Type.

A a = new B();

The Apparent Type is A because the compiler only knows that the object is of type A. As such at this time you cannot reference any of the B specific methods.

The Actual Type is B. You are allowed to cast the object (that is change its apparent type) in order to access the B specific methods.