Count property vs Count() method?

Question

Working with a collection I have the two ways of getting the count of objects; Count (the property) and Count() (the method). Does anyone know what

Answer 1

Short Version: If you have the choice between a Count property and a Count() method always choose the property.

The difference is mainly around the efficiency of the operation. All BCL collections which expose a Count property do so in an O(1) fashion. The Count() method though can, and often will, cost O(N). There are some checks to try and get it to O(1) for some implementations but it's by no means guaranteed.