Return index in LINQ query?

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Hello
I have a simple Linq query iterating thou two lists, when the the current item is the same, that item is returned. instead of the item being returned, I want the index of the item to be returned:

var indexes = from item1 in list1
              from item2 in list2
              where item1 == item2
              select item1; /*Instead of the Item of the first list being returned I want it to return the index of the first item*/

how to I archive this?

Posted 26-May-11 0:38am

Red&Black

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2 solutions

Solution 1

You can do it in this way:

C#

IEnumerable<int> indexes = (from item1 in list1
                              from item2 in list2
                              where item1 == item2
                              select list1.IndexOf(item1));

or if you want to return the first matching index, then simply apply the First extension:

C#

int firstIndex = (from item1 in list1
                              from item2 in list2
                              where item1 == item2
                              select list1.IndexOf(item1)).First<int>();

Hope it helped.

Posted 26-May-11 0:50am

Tarun.K.S

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Ashishmau · Accepted Answer · 2011-05-26T01:01:00

Solution 2

try this

SQL

var indexes = from item1 in list1
                      from item2 in list2
                      where item1 == item2
                      select list1.IndexOf(item1);

Posted 26-May-11 1:01am

Ashishmau

Comments

Red&Black 26-May-11 7:17am

Thank you very much this did the job (:

Tarun.K.S 26-May-11 7:37am

Wow, even I answered the same thing much before. Is there anything wrong in my code?