Virtual method dispatch mechanism in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the virtual method dispatch mechanism in C#?

It is the process where the program decides at runtime which version of a virtual method to call, based on the actual object's type, not the reference type.

beginner

How do you declare a method as virtual in C#?

By using the virtual keyword before the method return type in the base class.

beginner

What keyword is used to override a virtual method in a derived class?

The override keyword is used to provide a new implementation of a virtual method in a derived class.

intermediate

Why is virtual method dispatch important in object-oriented programming?

It enables polymorphism, allowing objects of different classes to be treated uniformly while invoking their specific behaviors at runtime.

intermediate

What happens if a method is not declared virtual but is redefined in a derived class?

The method in the derived class hides the base class method, but calls are resolved at compile time based on the reference type, not the object type.

Which keyword in C# allows a method to be overridden in derived classes?

A virtual

B override

C new

D abstract

The virtual keyword marks a method in the base class as overridable.

What determines which method implementation is called when using virtual methods?

A The object type at runtime

B The reference type

C The method name only

D The compiler settings

Virtual method dispatch uses the actual object's type at runtime to decide which method to call.

If a base class method is not virtual, what happens when a derived class defines a method with the same name?

A The derived method overrides the base method

B The base method is called always

C A compile error occurs

D The derived method hides the base method

Without virtual, the derived method hides the base method, and calls depend on reference type.

Which keyword must be used in the derived class to provide a new implementation of a virtual method?

A virtual

B new

C override

D sealed

The override keyword tells the compiler this method replaces the base virtual method.

What is the main benefit of virtual method dispatch?

A Faster code execution

B Runtime polymorphism

C Compile-time method selection

D Memory optimization

Virtual method dispatch enables runtime polymorphism, allowing flexible and dynamic method calls.

Explain how virtual method dispatch works in C# with an example.

Think about a base class with a virtual method and a derived class overriding it.

Describe the difference between method overriding and method hiding in C#.

Consider what happens when the base method is virtual or not.