Which answer is not a valid C# 4.0 variable definition?

Polymorphism. LET: public class BaseClass { public string DoWork() { return 'A'; } } public class DerivedClass : BaseClass { public new string DoWork() { return 'B'; } } IF: DerivedClass B = new DerivedClass(); BaseClass A = (BaseClass)B; A.DoWork(); What's the resulted output?

What will happen if the requested type conversion is not possible when using an 'as' operator ?

Which statement is True?

The main reflection methods to query attributes are contained in the...

Which of the following expressions give a compile time error?

When should the 'as' keyword be used in C# ?

What is the fundamental difference between double and decimal variable types?

Which of the following statements are correct?

Which of the following code snippets are the correct way to convert a Single into a String in C#? (Choose all that apply.)

What is the purpose of the yield keyword in C#?