What is the motivation behind “Use Extension Methods Sparingly?”

Question

I find them a very natural way to extend existing classes, especially when you just need to \"spot-weld\" some functionality onto an existing class.

Microsoft says, \"In

Answer 1

I follow a very simple rule with extension methods and helper classes.

Anytime I have a method that could be relegated to a static helper class I will weigh the usefulness of it in a general scope, do I really want this method to be shared? Is the meaning clear and useful to others?

If I can answer yes to this question I will create it to be an extension method. Where I have a shared library that among other things contains all of my Extension methods in 1 namespace with each class file defined as TypeNameExtension so it becomes very clear what to expect is inside that class so that you can easily locate the code.

If I question the need for a helper method as a globally accessible usage I will declare the method private static and leave it inside the owning class.