Is it possible to use Add or AddRange method on IEnumerable C#?

Alternatively, you can use ICollection, which has an Add(T) method. Unfortunately, List. AddRange isn’t defined in any interface.

How do I initialize an IEnumerable?

IEnumerable is just an interface and so can’t be instantiated directly. IEnumerable m_oEnum = new List() { “1”, “2”, “3” }; you can then pass this to anything expecting an IEnumerable . You cannot instantiate an interface – you must provide a concrete implementation of IEnumerable.

What is IEnumerable C# example?

IEnumerable in C# is an interface that defines one method, GetEnumerator which returns an IEnumerator interface. This allows readonly access to a collection then a collection that implements IEnumerable can be used with a for-each statement.

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 .

What is the difference between ADD and AddRange in C#?

Add is used to insert one element at a time in a collection. AddRange is used to add multiple elements. The add method inserts the item at the end of a collection. AddRange method is used to insert a set of records into a collection.

How use AddRange method in C#?

AddRange() method is used to add the objects/elements of a specified collection at the end of the list.

1. Syntax:
2. Example: int list declaration: List a = new List(); int array to be added to the list: int[] int_arr = { 100, 200, 300, 400 }; adding elements: a.AddRange(int_arr); Output: 100 200 300 400.

How do I get the first IEnumerable element?

We can get first item values from IEnumerable list by using First() property or loop through the list to get respective element. IEnumerable list is a base for all collections and its having ability to loop through the collection by using current property, MoveNext and Reset methods in c#, vb.net.

How do I find the value of an IEnumerable List?

Use a loop ? Or use ToList and convert it to List then you can access your value with index: var myList = list. ToList(); var count = myList[0].

Is IEnumerable faster than List?

We aren’t forcing the caller to convert their data structure to a List unnecessarily. 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.

Is IEnumerable faster than list?

Are arrays IEnumerable?

2 Answers. Arrays do implement IEnumerable> , but it is done as part of the special knowledge the CLI has for arrays. This works as if it were an explicit implementation (but isn’t: it is done at runtime).

What is difference between ADD and AddRange?

How can I add an item to an IEnumerable < T > collection?

The type IEnumerable does not support such operations. The purpose of the IEnumerable interface is to allow a consumer to view the contents of a collection. Not to modify the values. When you do operations like .ToList ().Add () you are creating a new List and adding a value to that list.

What is the purpose of the IEnumerable < T > interface?

The purpose of the IEnumerable interface is to allow a consumer to view the contents of a collection. Not to modify the values. When you do operations like .ToList ().Add () you are creating a new List and adding a value to that list.

Can a new IEnumerable object be added to an array?

What you can do, however, is create a new IEnumerable object (of unspecified type), which, when enumerated, will provide all items of the old one, plus some of your own. You use Enumerable.Concat for that: This will not change the array object (you cannot insert items into to arrays, anyway).

How to add items to a list in LINQ?

Also with Linq libraries you have an extension method that allows casting your IEnumerable to a List via IEnumerable.ToList () and you can add items to a list. THis moght not be the proper way though. With Linq libraries in your namespace you can do the following: