Is it better to return IEnumerable or list?
There’s a received wisdom that it’s always better to return the most specific interface – meaning the interface which has the smallest possible set of functions. By that token, since IEnumerable<T> is smaller than IList<T> you should return IEnumerable<T>.
What is the return type of IEnumerable?
IEnumerable has just one method called GetEnumerator. This method returns another type which is an interface that interface is IEnumerator. If we want to implement enumerator logic in any collection class, it needs to implement IEnumerable interface (either generic or non-generic).
Which is faster IEnumerable or list?
IEnumerable is conceptually faster than List because of the deferred execution. Deferred execution makes IEnumerable faster because it only gets the data when needed.
What is the difference between an IEnumerable and a list?
IEnumerable is read-only and List is not. IEnumerable types have 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.
Should I use collection or List C#?
The reason “why” you “should” use a Collection<T> instead of a List<T> is because if you expose a List<T> , then anyone who gets access to your object can modify the items in the list. Whereas Collection<T> is supposed to indicate that you are making your own “Add”, “Remove”, etc methods.
What is difference between List and IList in C#?
The main difference between List and IList in C# is that List is a class that represents a list of objects which can be accessed by index while IList is an interface that represents a collection of objects which can be accessed by index.
How do I return an IEnumerable class in C#?
The first method in the class that will be called is IEnumerable<int>. GetEnumerator() . If the call is coming from the same thread that instantiated the class, it will reset the state to 0 and return this . The next thing the calling code would do is to step the enumerator forward through IEnumerator<int>.
What are the differences between IEnumerable and IQueryable?
The major difference between IQueryable and IEnumerable is that IQueryable executes query with filters whereas IEnumerable executes the query first and then it filters the data based on conditions.
Which collection is faster in C#?
ListDictionary is faster than Hashtable for small collections (10 items or fewer). The Dictionary<TKey,TValue> generic class provides faster lookup than the SortedDictionary<TKey,TValue> generic class.
Which is better IQueryable or IEnumerable?
So if you working with only in-memory data collection IEnumerable is a good choice but if you want to query data collection which is connected with database `IQueryable is a better choice as it reduces network traffic and uses the power of SQL language.
Which is faster IEnumerable or IQueryable?
IQueryable is faster than IEnumerable. In addition to Munesh Sharma’s answer:IEnumerable loads data in-memory and then apply filters to it one by one but IQueryable apply filters all at once and return the result.
Is IQueryable faster than List?
GetList(context) might return an object backed by a custom LINQ provider (like an Entity Framework collection), then you probably want to leave the data cast as an IQueryable: even though your benchmark shows it being 20 times faster to use a list, that difference is so small that no user is ever going to be able to …
Why should I use IEnumerable?
IEnumerable is best to query data from in-memory collections like List, Array etc. IEnumerable doesn’t support add or remove items from the list. Using IEnumerable we can find out the no of elements in the collection after iterating the collection. IEnumerable supports deferred execution.
Should I use list or IList?
Basically, if you want to create your own custom List , say a list class called BookList , then you can use the Interface to give you basic methods and structure to your new class. IList is for when you want to create your own, special sub-class that implements List.
What is IEnumerable <> in C#?
IEnumerable is an interface defining a single method GetEnumerator() that returns an IEnumerator interface. It is the base interface for all non-generic collections that can be enumerated. This works for read-only access to a collection that implements that IEnumerable can be used with a foreach statement.
Is IQueryable faster than list?
Is IEnumerable lazy loading?
IEnumerable doesn’t support lazy loading.
Is array faster than list C#?
Short answer: In . NET List<T> and Array<T> have the same speed/performance because in . NET List is wrapper around Array .
Should I use collection or list C#?
Should I use IQueryable or IEnumerable?
IEnumerable: IEnumerable is best suitable for working with in-memory collection (or local queries). IEnumerable doesn’t move between items, it is forward only collection. IQueryable: IQueryable best suits for remote data source, like a database or web service (or remote queries).
Which one is better IEnumerable or IQueryable?
What is difference between IEnumerable and IQueryable?
Is IEnumerable immutable?
Just realized IEnumerable is immutable, what are other commonly used immutable generic interfaces?
Is IQueryable faster than IEnumerable?
Which loop is faster in C#?
The forloop is faster than the foreach loop if the array must only be accessed once per iteration.