# Source: https://docs.datadoghq.com/security/code_security/static_analysis/static_analysis_rules/csharp-best-practices/contains-not-any.md

---
title: Use Contains for simple equality
description: Datadog, the leading service for cloud-scale monitoring.
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  Docs > Datadog Security > Code Security > Static Code Analysis (SAST) > SAST
  Rules > Use Contains for simple equality
---

# Use Contains for simple equality

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## Metadata{% #metadata %}

**ID:** `csharp-best-practices/contains-not-any`

**Language:** C#

**Severity:** Warning

**Category:** Best Practices

## Description{% #description %}

When using only a simple comparison, use `Contains` instead of `Any` as it is more efficient in terms of resources allocation.

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```csharp
using System.Xml;

class MyClass {
    public static bool filter(IEnumerable<int> values, int target)
    {
        return values.Any(x => target == x);
    }
}
```

```csharp
using System.Xml;

class MyClass {
    public static bool filter(IEnumerable<int> values, int target)
    {
        return values.Any(x => x == target);
    }
}
```

## Compliant Code Examples{% #compliant-code-examples %}

```csharp
using System.Xml;

class MyClass {
    public static bool filter1(IEnumerable<int> values, int target)
    {
        return values.Contains(target);
    }
    public static bool filter2(IEnumerable<int> values, int target)
    {
        return values.Any(c => c > target);
    }
    public static bool filter3(IEnumerable<SomeType> values, int target)
    {
        return values.Any(c => c.Id == target);
    }
}
```
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