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C# 4.0 New Features


What are the new features introduced in c# 4.0?

This is very commonly asked c# interview question. This question is basically asked to check, if you are passionate about catching up with latest technological advancements. The list below shows a few of the new features introduced in c# 4.0. If you are aware of any other new features, please submit those using the from at the end of this post.

1. Optional and Named Parameters
2. COM Interoperability Enhancements
3. Covariance and Contravariance
4. Dynamic Type Introduction

20 comments:

  1. Hi Venkat,

    Can we hope an example for each new feature introduced in c#4.0

    ReplyDelete
  2. New featires in c# 4.0 -Lambda expression, LINQ

    ReplyDelete
  3. No, lambda expression and LINQ where introduced in Framework 3.0 before VS 2010.

    ReplyDelete
    Replies
    1. MVC3.0, EF4.1 including in VS2010, no need to install sepratly...

      Delete
    2. lambda expression and LINQ where introduced in Framework 3.5.

      Delete
  4. version comparability which mean we can execute the the project which is developed in earlier versions of .net framework.

    ReplyDelete
  5. Do u work with linq ? If yes how do u use linq?

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  6. How we can Say C# is Pure OOPS,If I Declare a Method With Static Keyword then it doesn't need to call with the help of Object.

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  7. Accessing data is easy if we are familiar with Linq concepts. We can travel through nodes in xml and can modify it as per our need. Instead of using DOM we can use Linq, we can add System.Data.Linq namespace to use it...

    ReplyDelete
  8. yes we need example for each of this features..could u please share here pragim..

    ReplyDelete
  9. Zip extension Method introduced in C# 4.0:

    What is the purpose of ZIP extension method? Explain with example.

    The new ZIP extension method introduced in C#4.0 merges two collection sequences by using a predicate function.It is a Combining operator.It combines items from one collection with items from second that are in the same position in the collection.

    If Collection A has N items and Collection B has N items (N = 1, 2, 3, 4...), the ZIP extension method will perform the operation as A[N] with B[N].


    Let us see an example

    Sample input


    List firstCollection = new List { 11,12,13,14,15 };

    List secondCollection = new List { 6,7,8,9,10 };



    Aim:

    To perform x + y

    Solution using ZIP extension method




    var firstCollection = new List { 11,12,13,14,15 };

    var secondCollection = new List { 6,7,8,9,10 };



    firstCollection

    .Zip(secondCollection, (a, b) => a + b)

    .ToList()

    .ForEach(i => Console.WriteLine(i));





    Result


    17

    19

    21

    23

    25



    Explanation:

    We are merging the two sequences by using the predicate function ((a, b) => a + b) and using the Foreach extension method performing the display action on each element.

    ReplyDelete
  10. Tuple:

    C#4.0 has introduce a new feature call Tuple.It is useful when we want to return more than one value from a method or function.

    class Program
    {
    static void Main(string[] args)
    {
    var returnValue = Calculate();
    string format =

    "Addition: {0}" + Environment.NewLine +

    "Subtraction: {1}" + Environment.NewLine +

    "Multiplication: {2}" + Environment.NewLine +

    "Division: {3}";

    string result = string.Format(format, returnValue.Item1, returnValue.Item2, returnValue.Item3, returnValue.Item4);

    Console.WriteLine(result);

    Console.ReadKey(true);

    }

    private static Tuple Calculate()

    {
    int num1 = 20;
    int num2 = 10;
    return Tuple.Create(num1+num2,num1-num2,num1 * num2,num1/num2);
    }

    }


    As can be seen that using Tuple we can return multiple values from the function/method in a better and readable way.

    ReplyDelete
  11. @Ganta Vini Don't you think Tuple should be Tuple in your case
    private static Tuple Calculate(){} as you are returning 4 values

    ReplyDelete
  12. why interfaces are introduced??already classes are present...then why???

    ReplyDelete
  13. where can we use enums???give me one real time example??

    ReplyDelete
    Replies
    1. Anywhere you want to limit the type that is used.

      enumerated Day {
      Monday = 1,
      Tuesday,
      Wednesday,
      Thursday,
      Friday,
      Saturday,
      Sunday
      }

      Used as Day . Wednesday;

      Delete
  14. Ever thought training in c# mobile using xamarin? The way teach is awesome and there are very little worthy modern tutorials with this technology.

    Most books are outdated or provide very little information on the entire technology. Videos I have found don't go past hello world and definitely do not explain.

    ReplyDelete
  15. In C# and Visual Basic, covariance and contravariance enable implicit reference conversion for array types, delegate types, and generic type arguments. Covariance preserves assignment compatibility and contravariance reverses it.

    ReplyDelete
  16. Dear sir if you know about WPF then please makes tutorials for us i would be very thanks full to you

    ReplyDelete

If you are aware of any other C# questions asked in an interview, please post them below. If you find anything missing or wrong, please feel free to correct by submitting the form below.

 
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