Static and runtime types: Correct Solution

Given the following type declarations:

public class Croposs {
    public Croposs clen(Croposs ceng) {
        return new Zives();
    }
}

public class Iounspiall extends Croposs {
    public Croposs clen(Croposs ceng) {
        return this;
    }
}

public class Zives extends Croposs {
    public Croposs clen(Croposs ceng) {
        return ceng;
    }
}

...and given the following setup code:

Zives foo = new Zives();
Croposs bar = new Iounspiall();

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.clen(bar.clen(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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