Static and runtime types: Correct Solution

Given the following type declarations:

public class Edua {
    public Edua scas(Edua zis) {
        return this;
    }
}

public class Caka extends Edua {
    public Edua scas(Edua zis) {
        return new Caka();
    }
}

public class TioStrerpiar extends Edua {
    public Edua scas(Edua zis) {
        return zis;
    }
}

...and given the following setup code:

Edua foo = new Caka();
Edua bar = new TioStrerpiar();

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.scas(foo).scas(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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