Why prefix C# interface names with an “I”

Question

What is the rationale behind this naming convention?

I don\'t see any benefit. The extra prefix just pollutes the API.

My thinking is inline with Konrad\'s respo

Answer 1

I always thought it was fun to use verbs for behavioral interfaces. This is a departure from the class naming convention of using nouns, but it allows the class to "speak" to its behavior.

class Dog: IBark

This does not work well for structural interfaces like WCF interfaces, but we don't need to have fun all the time.

to answer your question, think of the I as "implements" So...

class DogDataService : Dog, IDataService

this service class inherits from Dog and implements IDataService

I'm still not really answering your question, but the I is useful because you get naming collisions between namespace, class and interface.

namespace DataService
interface DataService
class DataService: DataService

so we end up with

namespace DataServices
interface IDataService
class DataService : IDataService

I think in reality, it's a sanity convention.