Why does the second for loop always execute faster than the first one?

Question

I was trying to figure out if a for loop was faster than a foreach loop and was using the System.Diagnostics classes to time the task. While running the test I noticed that

Answer 1

You should be using the StopWatch to time the behavior.

Technically the for loop is faster. Foreach calls the MoveNext() method (creating a method stack and other overhead from a call) on the IEnumerable's iterator, when for only has to increment a variable.