.Net Interview Questions and Answers – Part 1
1. What is .NET?
.NET is essentially a framework for software development. It is similar in nature to any other software development framework (J2EE etc) in that it provides a set of runtime containers/capabilities, and a rich set of pre-built functionality in the form of class libraries and APIs
The .NET Framework is an environment for building, deploying, and running Web Services and other applications. It consists of three main parts: the Common Language Runtime, the Framework classes, and ASP.NET.
2. How many languages .NET is supporting now?
When .NET was introduced it came with several languages. VB.NET, C#, COBOL and Perl, etc. .net Supports More than 44 languages.
3. How is .NET able to support multiple languages?
A language should comply with the Common Language Runtime standard to become a .NET language. In .NET, code is compiled to Microsoft Intermediate Language (MSIL for short). This is called as Managed Code. This Managed code is run in .NET environment. So after compilation to this IL the language is not a barrier. A code can call or use a function written in another language.
4. What is an application server?
As defined in Wikipedia, an application server is a software engine that delivers applications to client computers or devices. The application server runs your server code. Some well known application servers are IIS (Microsoft), WebLogic Server (BEA), JBoss (Red Hat), WebSphere (IBM).
5. What is inheritance?
Inheritance represents the relationship between two classes where one type derives functionality from a second type and then extends it by adding new methods, properties, events, fields and constants. C# support two types of inheritance:
– Implementation inheritance
– Interface inheritance
6. What is implementation and interface inheritance?
When a class (type) is derived from another class(type) such that it inherits all the members of the base type it is Implementation Inheritance.
When a type (class or a struct) inherits only the signatures of the functions from another type it is Interface Inheritance.
In general Classes can be derived from another class, hence support Implementation inheritance. At the same time Classes can also be derived from one or more interfaces. Hence they support Interface inheritance.
7. What is inheritance hierarchy?
The class which derives functionality from a base class is called a derived class. A derived class can also act as a base class for another class. Thus it is possible to create a tree-like structure that illustrates the relationship between all related classes. This structure is known as the inheritance hierarchy.
8. How do you prevent a class from being inherited?
In VB.NET you use the NotInheritable modifier to prevent programmers from using the class as a base class. In C#, use the sealed keyword.
9. Define Overriding?
Overriding is a concept where a method in a derived class uses the same name, return type, and arguments as a method in its base class. In other words, if the derived class contains its own implementation of the method rather than using the method in the base class, the process is called overriding.
10. Can you use multiple inheritance in .NET?
.NET supports only single inheritance. However the purpose is accomplished using multiple interfaces.