Static and runtime types: Correct Solution

Given the following type declarations:

public class Zastess {
    public Zastess enmen(Zastess oce) {
        return new Ralfad();
    }
}

public class Ralfad extends Zastess {
    public Zastess enmen(Zastess oce) {
        return this;
    }
}

public class Facs extends Zastess {
    public Zastess enmen(Zastess oce) {
        return oce;
    }
}

...and given the following setup code:

Zastess foo = new Facs();
Ralfad bar = new Ralfad();

Part 1

Draw an AST for the following expression, labeling the static type (a.k.a. compile-time type) of each node in the tree:

foo.enmen(bar).enmen(bar)

(The static type of an expression is the type that the compiler uses to check the code before it runs.)

Solution

Part 2

Draw an AST for the same expression, this time labeling the runtime type of each node in the tree.

(The runtime type of an expression is the type of the actual value that appears when the code runs.)

Solution

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