收益回报与收益选择 [英] yield return versus return select

问题描述

哪些是优点/这两种方法的缺点？

Which are the advantages/drawbacks of both approaches?

return items.Select(item => DoSomething(item));

与

foreach(var item in items)
{
    yield return DoSomething(item);
}

修改作为他们MSIL大致相当，哪一个你觉得更可读？

EDIT As they are MSIL roughly equivalent, which one you find more readable?

推荐答案

在收益率回报技术使C＃编译器生成的枚举器类幕后的同时，在选择调用使用一个标准的枚举器类参数化的委托。在实践中，不应该有一大堆，两者之间的差异，可能比在选择情况下的额外调用框架等，为代表。

The yield return technique causes the C# compiler to generate an enumerator class "behind the scenes", while the Select call uses a standard enumerator class parameterized with a delegate. In practice, there shouldn't be a whole lot of difference between the two, other than possibly an extra call frame in the Select case, for the delegate.

有关它的价值，围绕包装的lambda 的DoSomething 是那种毫无意义的为好;只是通过一个委托直接。

For what it's worth, wrapping a lambda around DoSomething is sort of pointless as well; just pass a delegate for it directly.

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