Multiple choice technology programming languages

Consider a Base Class 'A' and a Derived Class 'B'. Case 1 B b=new B(); A a= A(b); Case 2 A a=new A(); B b=B(a); Choose the correct option(s)

  1. Case 1 will compile and execute

  2. Case 2 will compile and execute

  3. Case 2 will compile but fail at runtime

  4. Both the Cases wont compile
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

Case 1 (B to A) is upcasting - a subclass reference can always be assigned to a superclass reference, so it compiles and runs. Case 2 (A to B) is downcasting - requires explicit cast syntax B b=(B)a. With the cast it compiles but fails at runtime if 'a' doesn't actually reference a B object (ClassCastException). Without cast, it won't compile.

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