How to replace for-loops with a functional statement in C#?

Question

A colleague once said that God is killing a kitten every time I write a for-loop.

When asked how to avoid for-loops, his answer was to use a functional language. However

Answer 1

Sometimes a for-loop is bad if there exists a more efficient alternative. Such as searching, where it might be more efficient to sort a list and then use quicksort or binary sort. Or when you are iterating over items in a database. It is usually much more efficient to use set-based operations in a database instead of iterating over the items.

Otherwise if the for-loop, especially a for-each makes the most sense and is readable, then I would go with that rather than rafactor it into something that isn't as intuitive. I personally don't believe in these religious sounding "always do it this way, because that is the only way". Rather it is better to have guidelines, and understand in what scenarios it is appropriate to apply those guidelines. It is good that you ask the Why's!