[Solved] What will happen when this code runs?class Animal {} class Dog extends Animal {} class Cat extends Animal {} public class Test { public static void main(String[] args) { Animal a = new Dog();... | Java

Java - Polymorphism

What will happen when this code runs?

class Animal {} class Dog extends Animal {} class Cat extends Animal {} public class Test { public static void main(String[] args) { Animal a = new Dog(); Cat c = (Cat) a; } }

ACompilation error due to invalid cast

BProgram runs without error

CRuntime ClassCastException

DDog object converted to Cat object

Step-by-Step Solution

Solution:

Step 1: Understand object and reference types
'a' refers to a Dog object but is cast to Cat, which is unrelated subclass.
Step 2: Identify runtime behavior
At runtime, JVM detects invalid cast and throws ClassCastException.
Final Answer:
Runtime ClassCastException -> Option C
Quick Check:
Invalid downcast causes runtime ClassCastException [OK]

Quick Trick: Invalid downcast throws ClassCastException at runtime [OK]

Common Mistakes:

Expecting compile-time error instead of runtime error
Assuming cast silently converts object type
Thinking program runs without error

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More Java Quizzes

What will happen when this code runs?

Step 1: Understand object and reference types

Step 2: Identify runtime behavior

Final Answer:

Quick Check:

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