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What is difference between IEnumerable and list?
2 Answers. One important difference between IEnumerable and List (besides one being an interface and the other being a concrete class) is that IEnumerable is read-only and List is not. So if you need the ability to make permanent changes of any kind to your collection (add & remove), you’ll need List.
Is a list An IEnumerable?
List implements IEnumerable, but represents the entire collection in memory. LINQ expressions return an enumeration, and by default the expression executes when you iterate through it using a foreach, but you can force it to iterate sooner using .
Is list faster than IEnumerable?
So it isn’t that IEnumerable is more efficient than list in a “performance” or “runtime” aspect. It’s that IEnumerable is a more efficient design construct because it’s a more specific indication of what your design requires.
When 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.
Which is faster IEnumerable or IQueryable?
IQueryable : IQueryable fetches the Record based on filter wise. 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 it better to use IEnumerable or List?
IEnumerable describes behavior, while List is an implementation of that behavior. When you use IEnumerable , you give the compiler a chance to defer work until later, possibly optimizing along the way. If you use ToList() you force the compiler to reify the results right away.
Is IEnumerable lazy loading?
IEnumerable doesn’t support lazy loading. IQueryable support lazy loading. Hence it is suitable for paging like scenarios.
Is it better to use IEnumerable or list?
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 …
How are IEnumerable and list used in C #?
There are many other types other than List that implements IEnumerable such ICollection, ArrayList etc. So if we have IEnumerable as parameter of any method, we can pass any collection types to the function. Ie we can have method to operate on abstraction not any specific implementation.
When to use IEnumerable, icollection, IList and list?
There is a very good article written by: Claudio Bernasconi’s TechBlog here: When to use IEnumerable, ICollection, IList and List A class that implement IEnumerable allows you to use the foreach syntax. Basically it has a method to get the next item in the collection.
What’s the difference between tolist and IEnumerable in Java?
IEnumerable describes behavior, while List is an implementation of that behavior. When you use IEnumerable, you give the compiler a chance to defer work until later, possibly optimizing along the way. If you use ToList() you force the compiler to reify the results right away.
How does the IEnumerable in a foreach work?
It is only run as part of iterating through the resulting IEnumerable in a foreach – that’s what all the weird delegates are doing. So, the first example evaluates the query immediately by calling ToList and putting the query results in a list.