IEnumerable Vs List

Question

List li = new List (); Animals n = new Animals(); n.Cat = 1; n.Dog = 2; n.tiger = 3; li.Add(n); Animals n1 = new Animals(); n1.Cat = 2; n1.Dog = 2; n1.tiger = 3; li.Add(n1); IEnumerable test= li; foreach (var item in test) { Console.WriteLine(item.Cat); } foreach (var item in li) { Console.WriteLine(item.Cat); } Console.Read(); What is the difference between Ienumerable and list.List implements the interface Ienumerable.so it Includes all methods of IEnumerable. Where should I use IEnumerable And List respectively. Please Explain me the difference with an example.

Jignesh Trivedi · Answer

hi List is also implements from IEnumerable interface. IEnumerable is an interface. List is a class that defines a generic collection IEnumerable doesn't allow random access where as List does allow random access using integral index. In term of performance iterating values from IEnumerable is much faster than iterating values from a List. hope this will help you.

Vulpes · Answer

Although you can't create an object from an interface you can create a variable of an interface type. You can then assign to this variable a reference to any object which implements the interface which enables you to write generic code. Here List implements IEnumerable and so a reference to an object of the former type can be assigned to a variable of the interface type. However you could just as well have assigned a reference to an Animal[] rather than a List to the variable 'test'. The subsequent code would still have worked fine because the compiler knows that both of these objects can be enumerated using foreach which is one of the hallmarks of the IEnumerable and generic IEnumerable interfaces. So you often see code written using interface variables where the programmer is wanting the code to be as generic as possible so that other types of object which implement the interface can simply be slotted in. If you're sure that you won't want to do this in a particular case you can use a variable of a specific type instead.

Iftikar Hussain · Answer

Hi Please refer the below link http://stackoverflow.com/questions/3628425/ienumerable-vs-list-what-to-use-how-do-they-work Regards Iftikar