C# Programming - MCQ Practice Questions

A student management system implements IComparable<Student> to sort students. Which method must be implemented?

What happens when a derived class constructor does not explicitly call the base class constructor in C#?

In a company payroll system, Employee is the base class with CalculateSalary() as virtual method. Manager and Intern classes override it differently. Why is this design preferred?

Which statement about abstract classes in C# is INCORRECT?

A gaming application needs to implement different weapons (Sword, Gun, Bow) with different attack methods. Which approach is most maintainable?

In a complex system where a class needs to inherit from multiple sources of functionality while maintaining a single base type, which C# feature is most appropriate?

A financial system implements IEquatable<Account> for comparing accounts. What is the primary benefit of implementing this interface?

In a real estate system, consider Property (base) with House and Apartment (derived). If Property has a sealed method CalculateTax(), what happens in House class?

What is the output of the following C# code? class Base { public virtual void Display() { Console.WriteLine("Base"); } } class Derived : Base { public override void Display() { Console.WriteLine("Derived"); } } Base obj = new Derived(); obj.Display();

In C#, what is the primary purpose of using an interface?

Which keyword in C# is used to prevent a class from being inherited?

What will be the result of the following C# code? class Animal { } class Dog : Animal { } Dog dog = new Animal(); // Line 1

Which of the following correctly demonstrates composition in C#?

In a banking application, you need to create a base class that cannot be instantiated but defines common properties for SavingsAccount and CheckingAccount. Which should you use?

In a logistics system, both Truck and Bicycle need to calculate delivery cost. Instead of duplicating code, you decide to use an interface. What advantage does this provide?

Which statement is TRUE about abstract methods in C#?

Consider a scenario where class X implements interfaces IA and IB, and both interfaces have a method named Process(). How should X implement this?

In a healthcare system, Doctor is a derived class from Employee. If you want to ensure that Doctor's constructor calls Employee's constructor before executing, which approach is correct?

In a real-time inventory management system, a Product class needs to track stock levels that should not be modified directly from outside the class. Which OOP principle should be applied here, and how?

Consider a payment processing system where PaymentProcessor is an abstract class with an abstract method ProcessPayment(). CreditCardProcessor and UPIProcessor are derived classes. What will happen if you try to instantiate PaymentProcessor directly in C#?