---
title: "How to optimize LINQ queries and C# collections using ReSharper suggestions?"  
description: "How to optimize LINQ queries and C# collections using ReSharper suggestions?"  
author: "Manish Sharma"  
published: 2026-08-18  
updated: 2026-08-18  
canonical: https://answers.mindstick.com/qa/117076/how-to-optimize-linq-queries-and-c-collections-using-resharper-suggestions  
category: "C# Development"  
tags: ["ReSharper", "LINQ", "csharp", "performance", "Refactoring"]  
reading_time: 1 minute  

---

# How to optimize LINQ queries and C# collections using ReSharper suggestions?

Writing efficient LINQ queries in C# is crucial to avoid unnecessary memory allocations and redundant sequence enumerations. **ReSharper** automatically flags inefficient LINQ expressions and provides instant quick-fixes (Alt+Enter) to optimize performance.

## Common Inefficient LINQ Patterns Identified by ReSharper

ReSharper identifies several common anti-patterns in C# LINQ usage, including:

- Using `Count() > 0` instead of `Any()`.
- Multiple enumerations of an `IEnumerable<T>` without caching.
- Redundant `ToList()` or `ToArray()` calls prior to filtering.

### Code Refactoring Example

The code sample below illustrates how ReSharper transforms an inefficient collection evaluation into an optimized version:

```
// Unoptimized pattern flagged by ReSharper
public bool HasActiveUsers(IEnumerable users)
{
    return users.Where(u => u.IsActive).Count() > 0;
}

// Optimized pattern suggested by ReSharper
public bool HasActiveUsersOptimized(IEnumerable users)
{
    return users.Any(u => u.IsActive);
}
```

## Performance Impact

By switching from `Count() > 0` to `Any()`, execution halts as soon as the first matching element is discovered, preventing a full iteration over the entire sequence.


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Original Source: https://answers.mindstick.com/qa/117076/how-to-optimize-linq-queries-and-c-collections-using-resharper-suggestions

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