The subtlety sixbrx mentions used to be present in C#, but it has been mostly fixed by moving the declaration of the foreach loop variable inside of the loop [1

The subtlety sixbrx mentions used to be present in C#, but it has been mostly fixed by moving the declaration of the foreach loop variable inside of the loop [1]. Like Python, C# has reference semantics. I'm surprised that Guido van Rossum didn't make a similar change when he broke backwards compatibility in Python 3. [1]http://blogs.msdn.com/b/ericlippert/archive/2009/11/12/closing-over-the-loop-variable-considered-harmful.aspx http://blogs.msdn.com/b/ericlippert/archive/2009/11/12/closi...