IEnumerable in linq [Answered]RSS

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  Capricon Use...

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  IEnumerable in linq

  Jun 02, 2016 10:21 AM|Capricon User|LINK

  i have two queries one is

  List<int> Scores = new List<int>() { 97, 92, 81, 60 };
  IEnumerable<int> queryHighScores =
              from a in Scores
              where a < 5
              select a;

  and the other is

         int[] numbers = { 12, 43, 44, 323, 44, 45, 34 };
          var query1 = from a in numbers
                       where a < 5 
                       select a;

  now anybody tell me what is IEnumerable and why we use this . both query return same result so why we use IEnumerable

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  A2H

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  Re: IEnumerable in linq

  Jun 02, 2016 01:26 PM|A2H|LINK

  Bakhtawar Ashiq

  what is IEnumerable and why we use this . both query return same result so why we use IEnumerable

  If you already know the output type of linq query then you can use IEnumerable. if you take the sample code you provided you are using IEnumerable<int> in which you already provided int as the return type.

  In certain cases if you are not sure on what the output type will be then we will use var.

  Additional references

  • Understanding Var and IEnumerable with LINQ
  • Var versus IEnumerable in LINQ
  Thanks,
  Aje
  My Blog | Dotnet Funda
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  Re: IEnumerable in linq

  Jun 03, 2016 05:13 AM|Capricon User|LINK

  what is the difference? both are same?

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  jignesht24

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  Re: IEnumerable in linq

  Jun 03, 2016 05:45 AM|jignesht24|LINK

  Hi,
  When you use "var" compiler determines the type.
  you can get the type using GetType() method.

  For your second query, return type is "System.Linq.Enumerable".
  also It would be good specify the return type when the type is already known.

  And keyword var and IEnumerable is not same because var can be any type which is decide by compiler at design time.
  hope this will help you.

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  Cole Wu

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  Re: IEnumerable in linq

  Jun 03, 2016 05:56 AM|Cole Wu|LINK

  Hi,

  Bakhtawar Ashiq

  what is the difference? both are same?

  A var variable must be initialized at the time of declaration.  but IEnumerable can do it: you could declare a IEnumerable variable like this:

  IEnumerable<int> queryHighScores;

  but you couldn't declare a var variable like this:

  var query1; 

  Best regards,

  Cole Wu