python中的yield == C＃中的yield return？

Question

I haven't been able to find any info on using JUST yield in C# (when used for a generator). Is this because C# always uses yield with return? (yield return Object)

I think I'm confusing myself since I was learning the same topic (generators) in python today aswell, and so far i've only seen yield used alone in Python..

Answer 1

yield keyword is introduced by C# 2.0 in order to implement iteartion easier. On the other hand it has some disadventages. Let's first look at the yield keyword.

public IEnumerable GetPowersofTwo()
{
   for (int i = 1; i < 10; i++)
       yield return (int)System.Math.Pow(2, i);
   yield break;
}

It is just a C# language feature. During compilation Compiler converts yield method and its class to instances of IEnumerable and IEnumerator implemented classes.

Criticism of the keyword yield

yield has a couple of drawbacks first of all it is designed to simplify implementing iterations. But it can be used to write very ill designed code (like goto). But using it for other than the intended purpose will make your code hard to follow. Second problem is that "yield" does not make sense in Object Oriented paradigm just like delegates.