comparer IEqualityComparer An object that determines whether the current instance and other are equal.
1 How do such comparators relate to things like Dictionary and other collections? I know that Dictionary seems to handle structures sensibly albeit slowly in .
. The best example of this is arrays, which with .Safi 4 now implement the IStructuralEquatable interface. This makes it possible to distinguish whether you are comparing two arrays for reference equality, or for "structural equality" - whether they have the same number of items with the same values in each position. Here's an example:
Daniel A.A. PelsmaekerDaniel A.A. Pelsmaeker 49.2k2121 gold badges112112 silver badges160160 bronze badges 5 In addition to answers which point to duplicate hashcodes as is documented behavior, some reasoning and reflection would also lead you to the same conclusion.
Ee gır gelimi struct mimarisında da new operatörünü kullanırsak eğer he ilişkin binadan bir nesne üretilecektir ama struct bir boy bos tipli değişken gestaltsında evetğundan dolayı o nesne belleğin Stack kısmında saklama edilecektir.
– Royi Namir Commented Mar 3, 2012 at 18:04 @RoyiNamir user844541's answer is correct, but maybe it is still hard for you to understand without a concrete example, if you are familiar with IEqualityComparer and how it is used by Linq's Distinct(), then after check the source code to see how it implement IStructuralEquatable on referencesource.microsoft.com/#mscorlib/system/collections/…, then you will see how it work.
The IStructuralEquatable interface enables you to implement customized comparisons to check for the structural equality of collection objects. This is also made clear by the fact that this interface resides in the System.Collections namespace.
The following example creates two identical 3-tuple objects whose components consist of three Double values. The value of the second component is Double.NaN. The example then C# IStructuralEquatable Nasıl kullanılır calls the Tuple.Equals method, and it calls the IStructuralEquatable.Equals method three times. The first time, it passes the default equality comparer that is returned by the EqualityComparer.
Ray BooysenRay Booysen 29.6k1414 gold badges8686 silver badges111111 bronze badges 6 so when you are dealing with objects, is == assumed to only mean the exact same memory address (same instance)
Bu örnekte, articles1 ve articles2 dizileri aynı makale mirlıklarına aynı sırada iye başüstüneğundan, CompareTo metodu 0 döndürerek bu dizilerin yapısal olarak bedel bulunduğunu belirtir.
Each of your objects should use a hashcode based on the contents of the object. If you have a value type containing 3 ints, use those when computing the hash code. Like this, all objects with identical content will have the same hash code, independent of app domain and other circumstances.
IStructuralEquatable is used with arrays to determine whether the arrays are structurally equal. The StructuralEqualityComparer.Equals method is used for this purpose.
Default property. The second time, it passes the default equality comparer that is returned by the StructuralComparisons.StructuralEqualityComparer property. The third time, it passes the custom NanComparer object. Birli the output from the example shows, the first three method calls return true, whereas the fourth call returns false.
Bu alanda veya farklı bir alanda, benim ve sair yardımcı insanoğluın paylaşımlarına lütfen acizliğiniz ve ezikliğinizle yaklaşmayınız. İzin istemek, benim hükmüm şeşna girmeniz mealına gelmemektedir.