What will happen if an invalid downcast is attempted in Java at runtime?
2025
What will happen if an invalid downcast is attempted in Java at runtime?
Answer: D. The code will compile but throw ClassCastException at runtime. — In Java, type casting involves converting an object reference from one type to another. When you attempt a downcast—converting a superclass reference to a…
- A.
The object will be automatically converted.
- B.
Java will ignore the cast and continue.
- C.
The compiler will throw a syntax error.
- D.
The code will compile but throw ClassCastException at runtime.
Attempted by 184 students.
Show answer & explanation
Correct answer: D
In Java, type casting involves converting an object reference from one type to another. When you attempt a downcast—converting a superclass reference to a subclass reference—the compiler checks if the cast is syntactically valid based on the declared types. If the code compiles successfully, it means the compiler cannot verify at compile-time whether the actual object is of the target subclass type. Consequently, the JVM performs a runtime check to ensure the object's actual class is compatible with the target type. If the object is not an instance of that subclass, the JVM throws a ClassCastException to prevent unsafe type access. Therefore, invalid downcasts do not cause compilation errors but result in a runtime exception.",