What's the difference between List<string> and IEnumerable<String>? [duplicate]

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Possible Duplicate:

What's the difference between IEnumerable and Array, IList and List?

What's the difference between the above two?

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A List<string> is a concrete implementation of IEnumerable<string>. The difference is that IEnumerable<string> is merely a sequence of string but a List<string> is indexable by an int index, can be added to and removed from and have items inserted at a particular index.

Basically, the interface IEnumerable<string> lets you stream the string in the sequence but List<string> lets you do this as well as modify and access the items in the lists in specific ways. An IEnumerable<string> is general sequence of string that can be iterated but doesn't allow random access. A List<string> is a specific random-access variable-size collection.

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different.

IEnumerable enables you to iterate through the collection using a for-each loop.

And IEnumerable just have method GetEnumerator.

And List it implement many interface like IEnumerable, Ilist, etc. So many function in List.

In performance IEnumerable faster than List.

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IEnumerable<T> is an interface. It must be implemented.

List<T> is one implementation of IEnumerable<T>

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One is an interface: http://msdn.microsoft.com/en-us/library/9eekhta0.aspx

The other is a class that implements that interface: http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx

Also, List is an array that grows when you add elements to it, while IEnumerable allows implementers to be used in a foreach.

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The first is a concrete List of strings, the other is any class implementing IEnumerable<string>