ASP.NET MVC FAQ

1. Can you have viewstate in ASP.NET MVC?

• Ans: No

2. Can you do unit testing of view in ASP.NET MVC?

• Ans: Yes

3. Is routing happens every time a page request or only first time?

• Ans: - Only first time
• - Shared Sub RegisterRoutes(ByVal routes As RouteCollection)

http://jinaldesai.net/asp-net-mvc-3-interview-questions/

Datastructures in .NET

a.       Stack:

·   FILO (first in last out)

·   Push(object o) – insert an object at top of stack

·   POP() – removes object at top of stack

·   Peek() – returns object at top of stack without removing

·   One of the classic examples of stack in .net framework is in memory management of value types.

·   There are non generic collection stack object (System.Collections.Stack) and generic collection stack object (System.Collections.Generic.Stack)

b.      Queue:

·   FIFO

·   Enqueue(object o) – add an object at end of queue

·   Dequeue() – remove object at beginning of queue

·   Peek() - return object at beginning of queue

·   First object entering to the Queue, exits first

·   One of the classic example of queue implementation in MSMQ

·   Queue is used in the highly reliable communication scenarios. Even if the message channel not available, messages are stored in the queue and transmitted once the channel is up.

·   There are non generic collection object (System.Collections.Queue) and generic collection object (System.Collections.Generic. Queue)

c.       Hashtable           

·   Hashtable stores key – value pair

·   Is organized based on the hash code of the key

·   Each element in hashtable is stored as DictionaryEntry object

·   A key cannot be null, but value can be

·   It is a non generic collection System.Collections type

·   Hashtable stores types of object

·   There is a type conversion required every time when we use hashtable

IDictionary, ICollection, IEnumerable, ISerializable, IDeserializationCallback, ICloneable

d.      Dictionary

·   Dictionary is similar to Hashtable (key-value pair storage)

·   It is a generic collection (System.Collections.Generics)

·   Type of the object to store in the dictionary should specify at compile time

·   Performance wise,  Dictionary is better option that Hashtable

IDictionary, ICollection<KeyValuePair>, IEnumerable<KeyValuePair>, IDictionary, ICollection, IEnumerable, ISerializable, IDeserializationCallback

e.      List

·   It is generics collection (System.Collections. Generics)

·   It represents strongly typed list of objects

·   Consider a scenario to store all the employee names of Satyam, then use List

·   No type conversion required hence preferred over ArrayList

IList, ICollection, IEnumerable, IList, ICollection, IEnumerable

f.        ArrayList

·   ArrayList is a non generic collection (System.Collections)

·   Size can be dynamically increase

·   ArrayList stores objects

·   Type conversion required every time when use AL
·  This affects the performance

Dependency Injection in .NET

Three Ways to Implement Dependency Injection in .NET Applications

http://www.devx.com/dotnet/Article/34066

Struct in C#.NET

            //NOTES: STRUCT

            // - struct is a value type 
            // - no need to use new keyword
            // - cannot inherit from struct(error: cannot derive from sealed type)
            // - struct allows properties/method which uses reference type.



namespace StructSample
{
    class Program
    {
        static void Main(string[] args)
        {
            Point p;
            p.x = 10;
            p.y = 20;

            p.name = "wgi";

            Console.WriteLine(p.Add());

            Console.Read();
        }
    }


    struct Point
    {
        public int x, y;

        public string name;

        public int Add() { return x + y; }
    }


    //class newPoint : Point
    //{
    //}
}

E-Book Gallery for Microsoft Technologies

http://social.technet.microsoft.com/wiki/contents/articles/11608.e-book-gallery-for-microsoft-technologies.aspx

Advantage of abstract class over interface

Advantage of abstract class over interface:

Consider versioning:

·         You cannot add members to interface without breaking the existing code.  

·         But you can safely add new members to abstract classes.

http://stackoverflow.com/questions/9143106/advantage-of-abstract-class-over-interface

Choosing between interface & abstract class:

·         Use interface when you want to implement multiple inheritance.

·         Use interface for decoupling

·         Use abstract class in case of frequent versioning scenario.

http://msdn.microsoft.com/en-us/library/ms229013.aspx

Compare 2 generic list

How to Compare 2 generic lists:

            List<int> list1 = new List<int> { 1, 2, 3, 5, 6 };

            List<int> list2= new List<int> { 1, 2, 3 };

Answer: if you are trying to see if 2 sets are equal, then the best approach is to check the except extension method on Enumerable class. And make sure that the result does not have any entries.

            var except = Enumerable.Except(list1, list2);

            if (except.Count() > 0)
                Console.Write("Not equal");
            else
                Console.Write("equal");;

Reference:

http://stackoverflow.com/questions/2270754/how-to-compare-two-generic-lists-in-c-sharp-3-0