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<T>. Keep in mind that the examples are a starting point to learn from as it is not possible to cover all situations.

✔️ Code will be added over time.

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

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⚪ json read using System.Text.Json;

⚪ JsonLibrary provides json read operations

⚪ ApplicationDataLibrary containers comparers

Sample

[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);
}

public class FirstNameComparer : IEqualityComparer<Person>
{
    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

public class Wrappers
{
    public static IEqualityComparer<Person> FirstNamEqualityComparer => 
        Equality<Person>.CreateComparer(p => p.FirstName);
    
    public static IEqualityComparer<Person> LastNamEqualityComparer => 
        Equality<Person>.CreateComparer(p => p.LastName);
    
    public static LambdaEqualityComparer<Person> FirstNameLambda => 
        new((p1, p2) => 
        p1.FirstName == p2.FirstName, x => x.FirstName.GetHashCode());
    
    public static LambdaEqualityComparer<Person> LastNameLambda => 
        new((p1, p2) => 
        p1.LastName == p2.LastName, x => x.LastName.GetHashCode());
}