Implementation inheritance in C#
Def: In object - oriented programming, there are two distinct types of inheritance — implementation inheritance and interface inheritance:
- Implementation inheritance means that a type derives from a base type, taking all the base type ’ s member fields and functions.
Des r: With implementation inheritance, a derived type adopts the base type ’ s implementation of each function, unless it is indicated in the definition of the derived type that a function implementation is to be overridden. This type of inheritance is most useful when you need to add functionality to an existing type, or when a number of related types share a significant amount of common functionality.
Ex:If you want to declare that a class derives from another class, use the following syntax:
class MyDerivedClass: MyBaseClass
{ // functions and data members here}
If a class (or a struct) also derives from interfaces, the list of base class and interfaces is separated by commas:
public class MyDerivedClass: MyBaseClass, IInterface1, IInterface2
{ // etc. }
For a struct, the syntax is as follows:
public struct MyDerivedStruct: IInterface1, IInterface2
{ // etc. }
If you do not specify a base class in a class definition, the C# compiler will assume that System.Object is the base class. Hence, the following two pieces of code yield the same result:
class MyClass // derives from System.Object
{ // etc.}
Because C# supports the object keyword, which serves as a pseudonym for the System.Object class, you can also write:
class MyClass: object // derives from System.Object
{ // etc.}
EX: public class Shape;
{ int x,y;
Public virtual string Draw(string Figure)
{Cons.wr.(Figure);}
}
Class Rectangle: Shape
{ public override string Draw(string Name)
{Cons.Wr(“Rectangle”);}
}
Дата добавления: 2015-09-18 | Просмотры: 561 | Нарушение авторских прав
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 |
|