C# IEnumerable Nasıl Kullanılır Aptallar için

C# IEnumerable Nasıl Kullanılır Aptallar için

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If an airline is "countable", this means that there MUST be a flight attendant present on the plane, whose sole job is to count:

Koleksiyonlar Beyninde Gezinmeyi Sağlamlar: IEnumerable, koleksiyonlar ortada kolaylıkla gezinmenizi sağlar. GetEnumerator metodu ile koleksiyonun her bir elemanına erişebilir ve bu elemanlar üzerinde iş yapabilirsiniz.

So unless you want to perform operations that are more efficient on the list, this really does mean lower performance.

If on the second house, I decide to alter the price (say add one million dollars to the price) - the entire list would change (the order is now different). "one at a time" and "all of them right now" are two different things.

By adding on a Where statement you aren't actually doing much of anything, you're just adding an extra filter to the query so that later on, when you actually evaluate the sequence (in this case, when ToList is called) those filters will all be applied.

What I do is make a class that implements both IEnumerator and IEnumerable. Make GetEnumerator() return itself and you birey iterate it like normal.

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

You don't have to open a book and learn how to traverse the tree - but simply use the foreach statement on that object and you're done.)

The major difference between IQueryable and IEnumerable is that IQueryable C# IEnumerable Nasıl Kullanılır executes query with filters whereas IEnumerable executes the query first and then it filters the data based on conditions.

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 C# IEnumerable Temel Özellikleri support Reset and guarantee that multiple passes will either return identical data or throw an exception; an ordinary IEnumerable whose collection was modified should be allowed to return 'sensible' data if it's C# IEnumerable Temel Özellikleri able to do so or throw an exception if it gönül'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, your class might not hold any collection in memory, but rather C# IEnumerable Kullanımı iterate over all files existing in a certain directory, or items in certain DB, or other unmanaged resources. IEnumerable emanet step in 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).

There's also the issues of deferred execution and unmanaged resources. IEnumerable takes use of the yield syntax, which mean you go over each item by-itself and emanet perform all kinds of computations before and after. And again, this happens one-by-one, so you don't have to hold all the collection when you start. The computations won't actually be performed until the enumeration begins (i.e. until you run the foreach loop).

Bu ovamızın müterakki satırlarında IEnumerator interface’ini detaylandırırken, kendi enumeratorümüzü oluşturmayıda hususşacağız. Amma şimdilik bu örneğimizde derme yahut saf strüktürlarının GetEnumerator metodunu kullanmamız meslekimizi yeterince C# IEnumerable Kullanımı görmektedir.

Here is why it loads twice kakım fewer items birli the first example on average. Let's say probability to find element at any position in the range of files is the same.