linq-query-syntax

Regarding LINQ query syntax... var foo = new List<int> { 1, 2 }; var boo = from n in foo where n > 1 select n; ...I always thought this syntax was limited to operating on IEnumerable . Or at least until I learned about IQueryable. And perhaps IObservable as well. But I recently noticed a suggestion that query syntax is based on duck typing . That story didn't look terribly convincing, until I found a site that is dedicated to LINQ to Tasks . LINQ to Tasks looks like it is wholly dependent on duck typing with query syntax! Ok, what is going on here? Is query syntax using duck typing or not?

Given a class like this: public class Stock { public Stock() {} public Guid StockID { get; set; } public string Description { get; set; } } Lets say I now have a List<Stock> . If I would like to retrieve a list of all the StockIDs and populate it into a IEnumerable or IList. Obviously I can do this. List<Stock> stockItems = new List<Stock>(); List<Guid> ids = new List<Guid>(); foreach (Stock itm in stockItems) { ids.Add(itm.StockID); } But is there some way I could use Linq to achieve the same result? I thought Distinct() might do it but couldn't work out how to achieve the desired result. var

I'm trying to get a handle on if there's a good time to use standard linq keywords or linq extension methods with lambda expressions. They seems to do the same thing, just are written differently. Is it purely a matter of style? var query = from p in Products where p.Name.Contains("foo") orderby c.Name select p; // or with extension methods: var query = Products .Where(p => p.Name.Contains("foo")) .OrderBy(p => p.Name); They're very similar with the second example being a bit more terse, but perhaps less expressive if you don't know what the => is doing. Other than writing terse code, are