C# Interview Questions Part I

1. What’s the implicit name of the parameter that gets passed into the class’ set method?

Ans. Value, and its datatype depends on whatever variable we’re changing.

2. How do you inherit from a class in C#?

Ans. Place a colon and then the name of the base class. Notice that it’s double colon in C++.

3. Does C# support multiple inheritance?

Ans. No, use interfaces instead.

4. When you inherit a protected class-level variable, who is it available to?

Ans. Classes in the same namespace.

5. Are private class-level variables inherited?

Ans. Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are.

6. Describe the accessibility modifier protected internal.

Ans. It’s available to derived classes and classes within the same Assembly (and naturally from the base class it’s declared in).

7. C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write?

Ans Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there’s no implementation in it.

8. What’s the top .NET class that everything is derived from?

Ans System.Object.

9. How’s method overriding different from overloading?

Ans. When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class.

10. What does the keyword virtual mean in the method definition?

Ans The method can be over-ridden.