https://github.com/karenpayneoregon/comparing-objects-csharp

Comparing objects
https://github.com/karenpayneoregon/comparing-objects-csharp

comparable compare csharp csharp11 iequalitycomparer

Last synced: 8 months ago
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Comparing objects

• Host: GitHub
• URL: https://github.com/karenpayneoregon/comparing-objects-csharp
• Owner: karenpayneoregon
• Created: 2021-05-06T22:22:11.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2022-11-30T14:17:57.000Z (over 3 years ago)
• Last Synced: 2025-03-23T18:17:33.371Z (12 months ago)
• Topics: comparable, compare, csharp, csharp11, iequalitycomparer
• Language: C#
• Homepage:
• Size: 94.7 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md

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README

          
# About

Provides various examples for comparing objects. Most examples on the web usually deal with simple list of string or int while code samples here show how to work with `List`. Keep in mind that the examples are a starting point to learn from as it is not possible to cover all situations.

:heavy_check_mark:  Code will be added over time.

![img](assets/unitTesting.png) ![img](assets/csharpSmall.png)

:heavy_check_mark: 11/30/2022 Updated to .NET Core 7 from .NET Core 5 which is out of support.

---

:white_circle: json read using System.Text.Json;

:white_circle: JsonLibrary provides json read operations

:white_circle: ApplicationDataLibrary containers comparers

## Sample

```csharp

[TestMethod]

[TestTraits(Trait.Distinct)]

public void FirstNameLastName_Equality_Comparer()

{

    var people = ReadPeopleFromFile;

    people.Add(people[0]);

    Assert.AreEqual(people.Count, 51);

    

    var distinct = people.Distinct(new FirstNameLastNameEqualityComparer());

    

    Assert.IsTrue(distinct.Count() == 50);

}

```

```csharp

public class FirstNameComparer : IEqualityComparer

{

    public bool Equals(Person x, Person y)

    {

        if (ReferenceEquals(x, y)) return true;

        if (ReferenceEquals(x, null)) return false;

        if (ReferenceEquals(y, null)) return false;

        if (x.GetType() != y.GetType()) return false;

        return x.FirstName == y.FirstName;

    }

    public int GetHashCode(Person obj)

    {

        return (obj.FirstName != null ? obj.FirstName.GetHashCode() : 0);

    }

}

```

### Wrappers

```csharp

public class Wrappers

{

    public static IEqualityComparer FirstNamEqualityComparer => 

        Equality.CreateComparer(p => p.FirstName);

    

    public static IEqualityComparer LastNamEqualityComparer => 

        Equality.CreateComparer(p => p.LastName);

    

    public static LambdaEqualityComparer FirstNameLambda => 

        new((p1, p2) => 

        p1.FirstName == p2.FirstName, x => x.FirstName.GetHashCode());

    

    public static LambdaEqualityComparer LastNameLambda => 

        new((p1, p2) => 

        p1.LastName == p2.LastName, x => x.LastName.GetHashCode());

}

```