Linq effectiveness comparison

Question

Hello Could You please advise me a book or any reference where I can find information about the Linq method comparision based on its effectiveness ? I am interested in becasue I want to use a correct method in any situation like use Any() instead of Count() > 0 and I would like to find any implementation details why one is better than others Thanks in advance

Vulpes · Answer

I think you'll be hard pressed to find a book which goes into this in the required depth though there's quite a lot about the LINQ extension methods with occasional hints at how they're implemented in this one: http://www.amazon.com/5-0-Nutshell-The-Definitive-Reference/dp/1449320104 For example I learned from this book that the Count() method checks internally whether the input sequence implements ICollection and if it does simply calls ICollection .Count. Consequently in those situations Count() > 0 should be faster than Any() which needs to start iterating through the collection to see if there's at least one element in the sequence. However if the input sequence doesn't implement ICollection  then the Count() method will need to iterate though the entire sequence to find out how many elements there are and so in that situation Any() should be much faster. Note that the above remarks apply to LINQ to objects. In the case of LINQ to SQL and Entity Framework I wouldn't necessarily assume that the position will be the same as it will depend on the relative effectiveness of the equivalent functions within the database itself.

Joginder Banger · Answer

hey Tamas if you want Exact Time Measurement of between process you try this method. It's a namespace must be use for Stopwatch class:- using System . Diagnostics ; Stopwatch sw = new Stopwatch (); sw . Start (); //....do stuff here --like your loops and another function. sw . Stop (); Console . WriteLine ( Elapsed={0}  sw . Elapsed ); after this function you can compare which is give best performance .

Tamas S · Answer

Hello I found this book and started to read but I could not find any part that compare the effectiveness of one method to other

Joginder Banger · Answer

Hi Tamas S Here is one link you can download this book. it's free of cost. http://www.c-sharpcorner.com/ebooks/free/78/linq-quick-reference-with-C-Sharp.aspx