C#.NET basics interview questions and answers

What is C#?

 C# (pronounced “C sharp”) is a simple, modern, object-oriented, and type-safe programming language.
 It will immediately be familiar to C and C++ programmers.
 C# combines the high productivity of Rapid Application Development (RAD) languages.

What are the types of comment in C#?

There are 3 types of comments in C#.
 Single line (//)
 Multi (/* */)
 Page/XML Comments (///).

What are the namespaces used in C#.NET?

Namespace is a logical grouping of class.
 using System;
 using System.Collections.Generic;
 using System.Windows.Forms;

What are the characteristics of C#?

There are several characteristics of C# are :
 Simple
 Type safe
 Flexible
 Object oriented
 Compatible
 Consistent
 Interoperable
 Modern

How does C# differ from C++?

 C# does not support #include statement. It uses only using statement.
 In C# , class definition does not use a semicolon at the end.
 C# does not support multiple code inheritance.
 Casting in C# is much safer than in c++.
 In C# switch can also be used on string values.
 Command line parameters array behave differently in C# as compared to C++.

What are the basic concepts of object oriented programming?

It is necessary to understand some of the concepts used extensively in object oriented programming.These include
 Objects
 Classes
 Data abstraction and encapsulation
 Inheritance
 Polymorphism
 Dynamic Binding
 Message passing.

Can you inherit multiple interfaces?

Yes. Multiple interfaces may be inherited in C#.

What is inheritance?

Inheritance is deriving the new class from the already existing one.

Define scope?

Scope refers to the region of code in which a variable may be accessed.

What is the difference between public, static and void?

 public :The keyword public is an access modifier that tells the C# compiler that the Main method is accessible by anyone.
 static :The keyword static declares that the Main method is a global one and can be called without creating an instance of the class. The compiler stores the address of the method as the entry point and uses this information to begin execution before any objects are created.
 void : The keyword void is a type modifier that states that the Main method does not return any value.