Difficulty: Easy
Correct Answer: Compiles and runs ok.
Explanation:
Introduction / Context:
This program examines how an interface constant (implicitly public static final) can be accessed. In Java, interface fields are constants available through the interface name, through implementing classes, and even (discouraged stylistically) via instances of implementing classes.
Given Data / Assumptions:
Concept / Approach:
Static members should be accessed with a type name, but the language permits instance-qualified access as well (compiles, may elicit a warning). Since all three references point to the same compile-time constant, no runtime behavior beyond assignments occurs.
Step-by-Step Solution:
i = test141.k; → legal though stylistically discouraged; resolves to Foo141.k. i = Test141.k; → legal; Test141 inherits the constant from Foo141. i = Foo141.k; → canonical form; directly references the interface constant. No output, no exceptions.
Verification / Alternative check:
Mark k as something else (e.g., 5) and observe no behavioral change beyond assigned value; still compiles and runs.
Why Other Options Are Wrong:
There is no compilation error; there is nothing thrown at runtime since we only assign a primitive constant.
Common Pitfalls:
Believing interface fields are instance members; assuming instance-qualified access is illegal (it is legal but discouraged).
Final Answer:
Compiles and runs ok.
Discussion & Comments