How can i use linq to retrieve the index of a collection/array[Answered] RSS

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  DonnieS

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  How can i use linq to retrieve the index of a collection/array

  Aug 01, 2013 06:43 PM|DonnieS|LINK

  How can i use linq to retrieve the index of a collection/array when in the example below, I know the Age, Year, and CatDesc.  For example I want to do the Linq equivalent of

   

  var cIndex = Select ? from cBudget where Age = 50 and Year = 2003 and CatDesc = "Housing"

   

  Thanks

   

  DonnieS

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  DonnieS

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  Re: How can i use linq to retrieve the index of a collection/array

  Aug 01, 2013 06:46 PM|DonnieS|LINK

  Here is the collection in question.

   

   public class cBudget
   {
       public int    Age {get;set;}
       public int    Year {get;set;}
       public string CatDesc {get;set;}
       public string Desc {get;set;}
       public decimal Amount {get;set;}
       public string DesReq {get;set;}
       public double Inflation {get;set;}
   }
  

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  Mikesdotnett...

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  Re: How can i use linq to retrieve the index of a collection/array

  Aug 02, 2013 12:26 AM|Mikesdotnetting|LINK

  Why do you want the index of the item when you can get a reference to the item through a straightforward query?

  var item = cBudget.FirstOrDefault(i => i.Age == 50 && i.Year == 2003 && i.CatDesc == "Housing");

  But if you do want the index for some purpose, you have to write your own extension method to get that. See the accepted answer from Slaks here: http://stackoverflow.com/questions/2471588/how-to-get-index-using-linq
   

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  DonnieS

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  Re: How can i use linq to retrieve the index of a collection/array

  Aug 02, 2013 12:31 AM|DonnieS|LINK

  - I would use a crystal ball if it gives me the index - Thanks very much.

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  DonnieS

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  Re: How can i use linq to retrieve the index of a collection/array

  Aug 02, 2013 12:43 AM|DonnieS|LINK

  Actually, I want the index to make changes to the row that fits that query  as in

   

  budget[index].Amount = NewlyUpdatedAmount

   

   

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  Mikesdotnett...

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  Re: How can i use linq to retrieve the index of a collection/array

  Aug 02, 2013 03:32 AM|Mikesdotnetting|LINK

  You would tyically do that like this:

  var item = cBudget.FirstOrDefault(i => i.Age == 50 && i.Year == 2003 && i.CatDesc == "Housing");
  if(item != null){
   item.Amount = NewlyUpdatedAmount;
  } 

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