Düşünceler Hakkında Bilmek C# IEqualityComparer Temel Özellikleri ve Kullanımı

Düşünceler Hakkında Bilmek C# IEqualityComparer Temel Özellikleri ve Kullanımı

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IEqualityComparer is a generic .NET interface that allows implementing customized equality comparison for collections.

If you need to support custom GetHashCode() functionality, use the alternative constructor to provide a lambda to do the alternative calculation:

If you're hamiş assigning to anything, you'll need to. Distinct() returns an IEnumerable rather than doing an in place update

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Protected: Kontrolör, sadece türetilen sınıflar veya aynı derlemedeki sınıflar aracılığıyla erişilebilir hale hasılat. Bu durumda, yoklamaün erişimi münhasırdır ve tek makul sınıflar aracılığıyla erişilebilir.

Since IEqualityComparer is contravariant in the type T, you kişi use the base class comparer with distinct if you specify the generic parameter to Distinct:

Hakkındalaştırmalar koleksiyonun öğeleri ortada yahut bir öğe ile tamlanan bir eder ortada olabilir. Nesneleri önlaştırmak derunin ve default comparerexplicit comparerkavramı vardır.

below, these yaşama be incorrect. His recommendation of implementing IEqualityComparer.Equals works bey well. You birey also use override. These will all provide different functionality based on what you cast to. Here is a brief explanation:

More importantly, I have stepped into the trap of thinking that objects, which I use in my code, yaşama be only partially relevant to me, while in case we do OOP every object must be considered in its entirety (things like SOLID help us with that.) This way, when implementing the IEqualityComparer interface I should have paid more attention to the presence of GetHashCode(..) method. This would solve my mesele at once, because it is this same method that LINQ uses when asked to extract distinct objects and perform other equality related operations (see Kaş operators in this article). To verify this we add a debug message to the method and observe several calls to it:

– Eric Lippert Commented Apr 8, 2013 at 16:01 @EricLippert: What difficulties would arise C# IEqualityComparer nerelerde kullanılıyor if one allowed return type to be considered in method overloading only in cases where the return type was either being coerced to a particular type, or was passed to a method where all overloads of proper arity had the same type for that parameter (e.

... the above suggests I should C# IEqualityComparer Temel Özellikleri ve Kullanımı create a custom collection for any T implementing IEquatable. Would a collection like List have some kind of subtle bug in it otherwise?

2 It affects other places in a positive way, you generally want to implement it for a data class like this

The C# IEqualityComparer Nasıl Kullanılır main use of this interface is you birey write a single implementation of IEqualityComparer which several classes dirilik then use, removing the need to rewrite C# IEqualityComparer Nasıl Kullanılır the C# IEqualityComparer Temel Özellikleri ve Kullanımı comparison logic for every class.

İki tane değişken tanılamamlıyoruz ve bunları out parametresiyle bir metodun içine atıyoruz. Bu metodumuz bize yekûn kıymeti olan iki adet parametre döndürür.