Use the following for Questions A program to test the...

Use the following for Questions A program to test the BankAccount, SavingsAccount, and CheckingAccount classes has these declarations: BankAccount $\mathrm{b}=$ new BankAccount (1400) ; BankAccount $s=$ new SavingsAccount (1000,0.04) ; BankAccount $c=$ new CheckingAccount (500) ; Which of the following will not cause a ClassCastException to be thrown? (A) ((SavingsAccount) b). addInterest(); (B) ((CheckingAccount) b). withdraw(200); (C) ((CheckingAccount) c). deposit(800) ; (D) ((CheckingAccount) s).withdraw(150); (E) ((SavingsAccount) $c$ ). addInterest();

Use the following for Questions
A program to test the BankAccount, SavingsAccount, and CheckingAccount classes has these declarations:
BankAccount $\mathrm{b}=$ new BankAccount (1400) ;
BankAccount $s=$ new SavingsAccount (1000,0.04) ;
BankAccount $c=$ new CheckingAccount (500) ;
Which of the following will not cause a ClassCastException to be thrown?
(A) ((SavingsAccount) b). addInterest();
(B) ((CheckingAccount) b). withdraw(200);
(C) ((CheckingAccount) c). deposit(800) ;
(D) ((CheckingAccount) s).withdraw(150);
(E) ((SavingsAccount) $c$ ). addInterest();

Key Concepts

Inheritance

Inheritance is an object-oriented programming concept where a class (child or subclass) inherits attributes and methods from another class (parent or superclass). This allows for code reuse and the creation of a hierarchical relationship between classes, forming the basis for polymorphism and dynamic behavior in the software.

Polymorphism

Polymorphism enables objects to be treated as instances of their parent class while allowing for the execution of subclass-specific behavior. This is achieved through method overriding and dynamic method binding, which permits the correct method implementation to be chosen at runtime, depending on the actual object type.

Downcasting

Downcasting is the process of casting a reference of a superclass to a subclass type. This is necessary when subclass-specific methods or fields need to be accessed through a reference that was originally declared as the superclass. It should be performed with caution, as an incorrect downcast can lead to runtime errors if the object is not actually an instance of the target subclass.

ClassCastException

A ClassCastException is a runtime error in Java that occurs when an object is cast to a class that it is not an instance of. This typically happens during downcasting, when the actual type of the object does not match the subclass to which it is cast, leading to an incompatible cast at runtime.

Runtime vs. Compile-Time Type Checking

Runtime vs. compile-time type checking distinguishes the verification process of object types. Compile-time checking ensures that type assignments and method calls adhere to declared types, while at runtime the actual object type is determined, allowing for polymorphic behavior. Misalignment between the declared and actual types during casting can result in runtime exceptions like ClassCastException.

Please give Ace some feedback