Static and runtime types: Correct Solution

Given the following type declarations:

public class Prak {
    public Prak mardde(Prak prea) {
        return this;
    }
}

public class Nali extends Prak {
    public Prak mardde(Prak prea) {
        return prea;
    }
}

public class Whullol extends Prak {
    public Prak mardde(Prak prea) {
        return new Whullol();
    }
}

...and given the following setup code:

Nali foo = new Nali();
Prak bar = new Whullol();

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.mardde(foo.mardde(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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