Asp.net Fundamentals Tutorial

 Q1. What is Managed or Unmanaged Code?

• Managed Code -“The code, which is developed in .NET framework is known as managed code. This code is directly executed by CLR with the help of managed code execution. Any language that is written in .NET Framework is managed code”.
• Unmanaged Code -The code, which is developed outside .NET framework is known as unmanaged code.“Applications that do not run under the control of the CLR are said to be unmanaged, and certain languages such as C++ can be used to write such applications, which, for example, access low - level functions of the operating system. Background compatibility with the code of VB, ASP and COM are examples of unmanaged code”.

 Q2.What is Boxing and Unboxing?

• Boxing:-Boxing is the process of converting a value type data type to the object or to any interface data type which is implemented by this value type. When the CLR boxes a value means when CLR is converting a value type to Object Type, it wraps the value inside a System.Object and stores it on the heap area in application domain.
• Unboxing:-Unboxing is also a process which is used to extract the value type from the object or any implemented interface type. Boxing may be done implicitly, but unboxing have to be explicit by code.

 Q3. Can “this” be used within a static method?

• We can't use this in static method because keyword 'this' returns a reference to the current instance of the class containing it. Static methods (or any static member) do not belong to a particular instance. They exist without creating an instance of the class and call with the name of a class not by instance so we can’t use this keyword in the body of static Methods, but in case of Extension Methods we can use it the functions parameters. Let’s have a look on “this” keyword.

 Q4. What is sealed class in c#?

• Sealed classes are used to restrict the inheritance feature of object oriented programming. Once a class is defined as a sealed class, the class cannot be inherited

 Q5. What are partial classes?

• A partial class is only use to splits the definition of a class in two or more classes in a same source code file or more than one source files. You can create a class definition in multiple files but it will be compiled as one class at run time and also when you’ll create an instance of this class so you can access all the methods from all source file with a same object.

 Q6.What is the Constructor Chaining in C#?

• constructor chaining is a way to connect two or more classes in a relationship as Inheritance, in Constructor Chaining every child class constructor is mapped to parent class Constructor implicitly by base keyword so when you create an instance of child class to it’ll call parent’s class Constructor without it inheritance is not possible.

 Q7.Can Multiple Catch Blocks executed in c#?

• we can use multiple Catches block with every try but when any Exceptions is throw by debugger so every catches match this exception type with their signature and catch the exception by any single catch block so that means we can use multiple catches blocks but only one can executed at once

 Q8.What are Indexer in C# .Net?

• Indexer allows classes to be used in more intuitive manner. C# introduces a new concept known as Indexers which are used for treating an object as an array. The indexers are usually known as smart arrays in C#. They are not essential part of object-oriented programming. An indexer, also called an indexed property, is a class property that allows you to access a member variable of a class using the features of an array.

 Q9. What is Virtual Method in C#?

• A virtual method is a method that can be redefined in derived classes. A virtual method has an implementation in a base class as well as derived the class. It is used when a method's basic functionality is the same but sometimes more functionality is needed in the derived class. A virtual method is created in the base class that can be overridden in the derived class. We create a virtual method in the base class using the virtual keyword and that method is overridden in the derived class using the override keyword.

 Q10. What is jagged array in C#.Net?

• A jagged array is an array whose elements are arrays. The elements of a jagged array can be of different dimensions and sizes. A jagged array is sometimes called an "array of arrays." A special type of array is introduced in C#. A Jagged Array is an array of an array in which the length of each array index can differ.

 Q11.What is LINQ in C#?

• LINQ stands for Language Integrated Query. LINQ is a data querying methodology which provides querying capabilities to .NET languages with a syntax similar to a SQL query LINQ has a great power of querying on any source of data. The data source could be collections of objects, database or XML files. We can easily retrieve data from any object that implements the IEnumerable interface.

 Q12. What is the difference between “dispose” and “finalize” variables in C#?

• Dispose - This method uses interface – “IDisposable” interface and it will free up both managed and unmanaged codes like – database connection, files etc.
• Finalize - This method is called internally unlike Dispose method which is called explicitly. It is called by garbage collector and can’t be called from the code.

 Q13. What is the difference between “finalize” and “finally” methods in C#?

• Finalize – This method is used for garbage collection. So before destroying an object this method is called as part of clean up activity.
• Finally – This method is used for executing the code irrespective of exception occurred or not.

 Q14. What is the difference between “out” and “ref” parameters in C#?

• “out” parameter can be passed to a method and it need not be initialized where as “ref” parameter has to be initialized before it is used.

 Q15. Explain String Builder class in C#?

• This will represent the mutable string of characters and this class cannot be inherited. It allows us to Insert, Remove, Append and Replace the characters. “ToString()” method can be used for the final string obtained from StringBuilder.

 Q16. What is a Cookie?

• Cookie is a lightweight executable program, which the server posts to client machines.
• Cookies store the identity of a user at the first visit of the Web site and validate them later of the next visits for their authenticity.
• The values of a cookie can be transferred between the user’s request and the server’s response.

 Q17.What is the difference between ASP Session State and ASP.Net Session State?

• ASP session state relies on cookies, Serialize all requests from a client, does not survive process shutdown, Can not maintained across machines in a Web farm.

 Q18.What are the major built in objects in Asp.net?

• Application
• Request
• Response
• Server
• Session
• Context
• Trace

 Q19.What is a PostBack?

• The process in which a Web page sends data back to the same page on the server.

 Q20. What is AutoPostBack?

• If you want a control to postback automatically when an event is raised, you need to set the AutoPostBack property of the control to True.

 Q21. What is a round trip?

• The trip of a Web page from the client to the server and then back to the client is known as a round trip.

 Q22.What are the types of Cookies in Asp.net?

• There are two types of Cookies available in Asp.net :
• .Session Cookie
• .Persistent Cookie.

 Q23. Explain the features of C#?

• Constructors and Destructors
• Properties
• Passing Parameters
• Arrays
• Main
• XML Documentation and
• Indexers

 Q24.What is the lifespan for items stored in ViewState?

• The items stored in ViewState live until the lifetime of the current page expires including the postbacks to the same page.

 Q25.Which is the parent class of the Web server control?

• The System.Web.UI.Control class is the parent class for all Web server controls.