Integ - Interface

Interfaces are a contract that contains only the signatures of methods, properties, and events as its members.

Interfaces are not classes.

In C#, interfaces are defined using the interface keyword.

An interface only contains the signatures of methods, properties, and events as its members.

The class implementing the interface is responsible for providing the implementation of the members.

Interfaces cannot be instantiated.

Interface members cannot contain any code that implement its members; only the signatures can.

A common naming convention is to begin all interface names with a capital I.

The modifiers of the members of an interface are all public by default.

When a class implements an interface, the class can invoke the interface members directly from the object level.

An interface can be implemented on a class using the colon (:) symbol.

An interface declares methods without a method body or implementation.

The class implementing the interface defines the methods and provides them with the implementation.

The method implementation in the class must have the same signature, parameters, and method name as defined in the interface. Otherwise, the compiler will return an error.

Interfaces ensure that the implementing classes implement all the methods and properties declared in the interface.

A class can inherit only one (1) base class, but a class can implement multiple interfaces.

When a class implements multiple interfaces, the implementing class must implement all the members of the interfaces.

To implement multiple interfaces, the colon (:) symbol is used, and the interfaces are declared in a comma-separated list.

An interface cannot contain instance variables or fields.

An interface may contain properties.

A property can access a private data member of the class.

A read (get) and write (set) property can be declared in an interface using the syntax: datatype propertyName { get; set; }.

The accessors (get and set) of an interface does not have a body.

The purpose of the accessors is to indicate the properties are read-write.

Properties declared in the interface are used to access the private variables declared on the class.