INTERFACE

Syntax:
public interfaceIList : ICollection, IEnumerable
{
int Add (object value);                // methods
bool Contains (object value);
...
bool IsReadOnly { get;}                // property
...
object this [int index] { get; set;}  // indexer}

•Interface = purely abstract class; only signatures, no implementation.

•May contain methods, properties, indexersand events
(no fields, constants, constructors, destructors, operators, nested types).

•Interface members are implicitly public abstract(virtual).

•Interface members must not be static.

•Classes and structs may implement multiple interfaces.•Interfaces can extend other interfaces