Linq: how to share parameters between lambda expressions ?

Linq: how to share parameters between lambda expressions ? | Microsoft Share Point

Mon, 18 May 2009 22:57:30 GMT

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re: Linq: how to share parameters between lambda expressions ?

Fabien Lavocat — Wed, 17 Jun 2009 22:37:32 GMT

That a very good article! Thanks a lot. Before reading it, I didn't know .SelectMany method

re: Linq: how to share parameters between lambda expressions ?

Christian Schiffer — Tue, 04 Aug 2009 20:20:07 GMT

Nice posting and nice picture.

Off topic: would you post a larger version of that picture? Prefably full hd (1920*1080 for instance, I so much would like it as my desktop background :)

re: Linq: how to share parameters between lambda expressions ?

mitsu — Wed, 12 Aug 2009 15:42:17 GMT

@Christian: you can now click on the picture and jump to the original one. I love this picture too ! :p

re: Linq: how to share parameters between lambda expressions ?

Henri — Wed, 26 Aug 2009 12:29:44 GMT

This is the first really good explanation i see for how 'let' works and what it is used for. Thanks very much.

re: Linq: how to share parameters between lambda expressions ?

Owen Emlen — Thu, 27 Aug 2009 02:52:50 GMT

How come not orderby tmp.I? Or is it a typo?

var q =

from tmp in

(from s in values

select new { S = s, I = Convert.ToInt32(s) })

where tmp.I > 10

orderby tmp.S

select tmp.S;

re: Linq: how to share parameters between lambda expressions ?

NonGT — Thu, 27 Aug 2009 03:30:30 GMT

Nice article! It does clearly explain me what exactly the "let" keyword.

Thank you! :)

re: Linq: how to share parameters between lambda expressions ?

mitsu — Thu, 27 Aug 2009 12:36:44 GMT

Thanks for your comments.

@Owen: yes, typo mistake. thanks

re: Linq: how to share parameters between lambda expressions ?

BMavi — Fri, 28 Aug 2009 22:38:35 GMT

Thanks Mitsu, Good examples for understanding 'let' and 'SelectMany', never used before. Really appreciate your efforts.

re: Linq: how to share parameters between lambda expressions ?

Arun George John — Mon, 31 Aug 2009 08:49:43 GMT

Nice article. Never used the "let" keyword before, but this made it easy to understand!

Thanks!

re: Linq: how to share parameters between lambda expressions ?

Lou Gutnicki — Mon, 31 Aug 2009 21:30:57 GMT

Excellent article.

Clearly written.

Thanks

re: Linq: how to share parameters between lambda expressions ?

Kulveer — Tue, 01 Sep 2009 00:23:17 GMT

Nice article about Let and SelectMany.

Thanks

re: Linq: how to share parameters between lambda expressions ?

Kulveer — Tue, 01 Sep 2009 00:25:03 GMT

Nice blog

http://aspnetcsharp4.blogspot.com

Thanks

re: Linq: how to share parameters between lambda expressions ?

aganya — Fri, 04 Sep 2009 14:56:40 GMT

very nice article :-)

re: Linq: how to share parameters between lambda expressions ?

Pravat Maskey — Thu, 10 Sep 2009 12:41:06 GMT

Nice job dude, I know let now :)

re: Linq: how to share parameters between lambda expressions ?

Jignesh — Fri, 18 Sep 2009 10:22:18 GMT

Good artical man, thanx to heighlity 'let' and 'SelectMany', many of us never used them before.

re: Linq: how to share parameters between lambda expressions ?

SoCal — Tue, 22 Sep 2009 00:13:37 GMT

Great article! You explain a lot of stuff in a short article. Thanks.

re: Linq: how to share parameters between lambda expressions ?

HaoLT — Wed, 23 Sep 2009 19:38:50 GMT

I have a dificult mather that using LinQ.

Usually, Linq is used with object is a pointer set [] or <template> type. I have a array, must i have convert to these type above?

re: Linq: how to share parameters between lambda expressions ?

mitsu — Thu, 24 Sep 2009 00:34:06 GMT

Not sure to understand..

Linq always starts with a typed enumeration (generic). Arrays are typed enumerations, so you can start a Linq query from "values" if "values" is an int[] for example.

re: Linq: how to share parameters between lambda expressions ?

HaoLT — Thu, 24 Sep 2009 20:03:52 GMT

Let me add more infomation:

// Want to select some items with "Where" statement

Array test1; // Can't use "Where" statement

test1. Where (item => item = 2); // incorrect syntact

int[] test2; // Can use "Where" statement

test2.Where(item => item = 2); // correct syntact

//To using "Where" statement, must i convert from array to [] int

re: Linq: how to share parameters between lambda expressions ?

mitsu — Thu, 24 Sep 2009 23:35:02 GMT

If test1 contains integers, yes you have to convert it. As I said the enumeration must be typed.

You can 'type' your array without generating a new one. You can just write: test1.Cast<int>().Where(...)

re: Linq: how to share parameters between lambda expressions ?

HaoLT — Fri, 25 Sep 2009 18:30:10 GMT

I have just begin with LinQ. Thank about your guide.

I think it readly help me.

re: Linq: how to share parameters between lambda expressions ?

Bala — Fri, 02 Oct 2009 15:57:47 GMT

Very Nice article,Excellent one!!

Thanks..

re: Linq: how to share parameters between lambda expressions ?

François Vallernaud — Fri, 23 Oct 2009 12:14:08 GMT

Before reading your article i was using KeyValuePair to do the same thing

.Select(s => new KeyValuePair<string,int>(s, Convert.ToInt32(s)))

.OrderBy(kvp => kvp.Value)

....

I agree that your solution is much more confortable

re: Linq: how to share parameters between lambda expressions ?

mitsu — Fri, 23 Oct 2009 12:28:55 GMT

Agree with you François. Just keep in mind that the let keyword can only be used in the sql-like syntax of Linq.