如何检查IEnumerable是null还是空？ [英] How to check if IEnumerable is null or empty?

问题描述

我喜欢 string.IsNullOrEmpty 方法。我喜欢有一些东西，将允许相同的功能IEnumerable。有这样吗？也许有一些收集帮助类？我要求的原因是在如果语句代码看起来杂乱，如果模式（mylist！= null&& mylist.Any ））这将是更清洁有 Foo.IsAny（myList）。

I love string.IsNullOrEmpty method. I'd love to have something that would allow the same functionality for IEnumerable. Is there such? Maybe some collection helper class? The reason I am asking is that in if statements the code looks cluttered if the patter is (mylist != null && mylist.Any()). It would be much cleaner to have Foo.IsAny(myList).

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推荐答案

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Sure you could write that:

public static class Utils {
    public static bool IsAny<T>(this IEnumerable<T> data) {
        return data != null && data.Any();
    }
}

但是，注意并非所有序列都是可重复的; 我更喜欢只走一次，以防万一。

however, be cautious that not all sequences are repeatable; generally I prefer to only walk them once, just in case.

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