C# 0 The Complete Reference

PART I

C h a p t e r   1 1 :  

I n h e r i t a n c e  

271

PART IPART I

The output from this program is shown here:

Info for t1:

Triangle is isosceles

Width and height are 4 and 4

Area is 8

Info for t2:

Triangle is right

Width and height are 8 and 12

Area is 48

The

Triangle

 class creates a specific type of 

TwoDShape

, in this case, a triangle. The 

Triangle

 class includes all of 

TwoDShape

 and adds the field 

Style

, the method 

Area( )

, and 

the method 

ShowStyle( )

. A description of the type of triangle is stored in 

Style

;

Area( )

computes and returns the area of the triangle; and 

ShowStyle( )

 displays the triangle style.

Notice the syntax that 

Triangle

 uses to inherit 

TwoDShape

:

class Triangle : TwoDShape {

This syntax can be generalized. Whenever one class inherits another, the base class name 

follows the name of the derived class, separated by a colon. In C#, the syntax for inheriting 

a class is remarkably simple and easy to use.

Because

Triangle

 includes all of the members of its base class,