En C# IEnumerable Nedir Sırları

En C# IEnumerable Nedir Sırları

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So is it faster to use List over IEnumerable? Only if you want to prevent a query from being executed more than once. But is it better overall? Well in the above, Leopards and Hyenas get converted into single SQL queries each

Anything in .Kemiksiz that you hayat iterate over implements IEnumerable. If you're building your own class, and it doesn't already inherit from a class that implements IEnumerable, you güç make your class usable in foreach statements by implementing IEnumerable (and by creating an enumerator class that its new GetEnumerator method will return).

. If you need the results to be evaluated at once (say, you're mutating the structures you're querying later on, or if you don't want the iteration over the IEnumerable to take a long time) use a list.

Olur. Şu esas denli hiç IEnumerable ve IEnumerator interfacelerini kullanmadım diyebiliriz. Isteklendirmek elkızı şimdi bu interfaceleri hiçbir tenha ele alalım ve bu sırada fevkdaki satırlarda bahsettiğimiz GetEnumerator metodunuda tam teferruatlı masaya yatıralım.

Said in a very simple way, that any object implementing this interface will provide a way to get an enumerator. An enumerator is used with the foreach bey one example.

Basically it has a method to get the next item in the collection. It doesn't need the whole collection to be in memory and doesn't know how many items are in it, foreach just keeps getting the next item until it runs out.

// but this throws an exception, because the pointer or link to the // database namely the DbContext called MyEntities no longer exists.

For small result sets this is likely to be a single trip, for large ones you're sending a request for more rows from the results, but it doesn't re-run the entire query.

Nobody mentioned one crucial difference, ironically answered on a question closed as a duplicated of this. IEnumerable is read-only and List is not.

Marc GravellMarc Gravell 1.0m271271 gold badges2.6k2.6k silver badges2.9k2.9k bronze badges 1 1 The mistake with "Reset" was with just having one type of enumerable. IMHO, there should have been an IMultipassEnumerable, inheriting IEnumerable, which would support Reset and guarantee that multiple passes will either return identical veri or throw an exception; an ordinary IEnumerable whose collection was modified should be allowed to return C# IEnumerable Temel Özellikleri 'sensible' veri if it's able to do so or throw an exception if it sevimli't, and an ISafeEnumerable, which would be expected to work sensibly (without throwing an exception) even if a collection changes. A bit late now to change things, though.

And that might be useful and more efficient in certain cases. For example, C# IEnumerable Nasıl Kullanılır your class might hamiş hold any collection in memory, but rather iterate over all files existing in a certain directory, or items in certain DB, or other unmanaged resources. IEnumerable güç step in C# IEnumerable Temel Özellikleri and do it for you (you could also do it without IEnumerable, but IEnumerable "fits" conceptually, plus it gives you the benefit of being able to use the object produced in a foreach loop).

a reset on enumerators, but this is largely a C# IEnumerable Temel Özellikleri design C# IEnumerable Kullanımı mistake and shouldn't be used (it is even a formal requirement in the spec that iterator blocks throw an exception if you call it).

IEnumerable is an interface that defines one method GetEnumerator which returns an IEnumerator interface, this in turn allows readonly access to a collection. A collection that implements IEnumerable dirilik be used with a foreach statement.

Why does the Clausius inequality involve a single term/integral if we consider a body interacting with multiple heat sources/sinks?