Question

Consider this:

Requisite:

//The alphabet from a-z List<char> letterRange = Enumerable.Range('a', 'z' - 'a' + 1) .Select(i => (Char)i).ToList(); //97 - 122 + 1 = 26 letters/iterations 

Standard foreach:

foreach (var range in letterRange) {     Console.Write(range + ','); } Console.Write('\n'); 

Inbuilt foreach:

letterRange.ForEach(range => Console.Write(range + ',')); //delegate(char range) works as well Console.Write('\n'); 

I have tried timing them against each other and the inbuilt foreach is up to 2 times faster, which seems like a lot.

I have googled around, but I can not seem to find any answers.

Also, regarding: In .NET, which loop runs faster, 'for' or 'foreach'?

for (int i = 0; i < letterRange.Count; i++) {     Console.Write(letterRange[i] + ','); } Console.Write('\n'); 

Doesn’t act execute faster than standard foreach as far as I can tell.

Answer 1

I think your benchmark is flawed. Console.Write is an I/O bound task and it’s the most time consuming part of your benchmark. This is a micro-benchmark and should be done very carefully for accurate results.

Here is a benchmark: http://diditwith.net/PermaLink,guid,506c0888-8c5f-40e5-9d39-a09e2ebf3a55.aspx (It looks good but I haven’t validated it myself). The link appears to be broken as of 8/14/2015