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Update AV1800: Consider using Any() to determine whether an IEnumerable<T> is empty #375

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dennisdoomen merged 1 commit into from
Mar 29, 2026
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Update AV1800: Consider using Any() to determine whether an IEnumerable<T> is empty #375

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2 changes: 0 additions & 2 deletions _rules/1800.md
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Expand Up @@ -5,5 +5,3 @@ title: Consider using `Any()` to determine whether an `IEnumerable<T>` is empty
severity: 3
---
When a member or local function returns an `IEnumerable<T>` or other collection class that does not expose a `Count` property, use the `Any()` extension method rather than `Count()` to determine whether the collection contains items. If you do use `Count()`, you risk that iterating over the entire collection might have a significant impact (such as when it really is an `IQueryable<T>` to a persistent store).

**Note:** If you return an `IEnumerable<T>` to prevent changes from calling code as explained in [{{ site.default_rule_prefix }}1130](/member-design-guidelines#{{ site.default_rule_prefix }}1130), and you're developing in .NET 4.5 or higher, consider the new read-only classes.