IEnumerable.Any(Func)何时返回值? [英] When does IEnumerable.Any(Func) return a value?

问题描述

最近，我在与我合作的代码库中看到了一些代码，ReSharper提供了将其重构为collection.Any(Func< bool >)的代码.

I recently saw a bit of code in a codebase I work with, where ReSharper offered to refactor it to collection.Any(Func< bool >).

我想知道这样做对性能的影响.假设我有一个看起来像这样的电话:

I'm wondering about the performance impacts of this. Say I have a call that looks like this:

bool hasEvenValue = collection.Any(i => (i % 2) == 0);

...还有看起来像这样的数据...

...And data that looks like this...

{ 1, 2, 3, 5, 3, 5, 1, 3, 5, 2 }

Enumerable.Any()何时返回值?在这种情况下，第二个数据元素，还是会在返回true之前处理每个单个元素?

When does Enumerable.Any() return the value? The second data element, or will it process every single element before returning true, in this instance?

推荐答案

只要看到匹配的元素，它就会立即返回；否则，它会处理整个序列.

It returns as soon as it sees a matching element, or if none it processes the whole sequence.

因此，它比使用.Count(...) != 0(也更具可读性和语义意义)更好.

For that reason it is better than using .Count(...) != 0 (also more readable and semantically meaningful).

这篇关于IEnumerable.Any(Func)何时返回值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！