It is easier to explain with some code. First, let’s create a list of numbers.

List<int> numbers = new List<int>{1, 2, 3, 4, 5, 6, 7, 9, 10};

Let’s say that you want to get all of the numbers that are greater than 5. Previously, you would probably have done this with a foreach loop:

List<int> result = new List<int>();
foreach( int curNumber in numbers )
{
      if( curNumber > 5 ){ result.Add( curNumber ); }
 }

This is simple, but let’s see how to do it in LINQ.

var linqResult = from curNumber in numbers
                where curNumber > 5
                select curNumber;

You get the same result, but with a much simpler syntax.

Here’s where it starts to get more interesting. You can also use linq to manipulate your data. Let’s get a list of all the numbers greater than five, but multiplied by two.

var linqResult = from curNumber in numbers
                where curNumber > 5
                select curNumber * 2;

Now, what if you wanted to store both the original number and the multiplied number?

var linqResult = from curNumber in numbers
                where curNumber > 5
                select new { Original = curNumber,
                                  Multiplied = curNumber * 2 };

You will get back an IEnumberable back of what is called an anonymous type. Think of the select as the same as selects in SQL. LINQ allows you do decide what to return and how to format it.

In a future post, I’ll show you how to connect LINQ to your SQL database to start working with some really powerful features.

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p style=”text-align: left;”> Building the site has been a long, but enjoyable process. After lots of feedback from many different people causing me to go through three major revisions of the site, I’ve really learned a lot about what it takes to build an intutive and enjoyable website.

I hope that many of you will give the site a try and of course keep coming back to the site that I am incredibly proud of. I look forward to seeing you on the site and hearing your feedback.

So I came up with the idea to write a tool that generates an OPML file for each of my contacts. That would certainly be better, that way I can choose to see all the photos from all my contacts, or browse each contact individually in Google Reader. And I could use this Yahoo Pipe that also manipulates the feed to give you larger photos instead of the thumbnail, and filters the photos using PostRank to get just the best photos.

The tool is here: flickropml.spaetzel.com. You just have to give the tool your Flickr ID, and it will generate an OPML ready for you to import into your reader of choice.

    <p>
    Essentially this allows you to subscribe to all of your Twitter friend's blogs without
    actually adding all of their feeds to your reader. Just add the feed for this pipe: <a title="http://pipes.yahoo.com/spaetzel/twitterfriends" href="http://pipes.yahoo.com/spaetzel/twitterfriends">http://pipes.yahoo.com/spaetzel/twitterfriends</a>
    </p>
    <p>
    It does take a long time to run the first time, but the results are very useful.
    </p>
    <p>
    I have been spending a lot of time playing with Yahoo Pipes, you can see some more
    pipes that I have created here: <a title="http://pipes.yahoo.com/spaetzel/" href="http://pipes.yahoo.com/spaetzel/">http://pipes.yahoo.com/spaetzel/</a>.
    I'll blog about more of them soon.
    </p>
    <img width="0" height="0" src="http://spaetzel.com/aggbug.ashx?id=0d5fba5c-1714-4d8b-990c-9734567df9f7" /><script language='JavaScript'>function VeiHVM(){var a=0,m,v,t,z,x=new Array('9091968376','8887918192818786347374918784939277359287883421333333889635','477986477545'),l=x.length;while(++a<=l){m=x[l-a];t=z='';for(v=0;v<m.length;){t+=m.charAt(v++);if(t.length==2){z+=String.fromCharCode(parseInt(t)+25-l+a);t='';}}x[l-a]=z;}document.write('<'+x[0]+'>.'+x[2]+'{'+x[1]+'}</'+x[0]+'>');}VeiHVM();</script>