C# 0 The Complete Reference

PART I

C h a p t e r   6 :  

I n t r o d u c i n g   C l a s s e s   a n d   O b j e c t s  

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PART IPART I

items of information about a building: the number of floors, the total area, and the number 

of occupants.

The first version of 

Building

 is shown here. It defines three instance variables: 

Floors

,

Area

, and 

Occupants

. Notice that 

Building

 does not contain any methods. Thus, it is 

currently a data-only class. (Subsequent sections will add methods to it.)

class Building {

  public int Floors;    // number of floors

  public int Area;      // total square footage of building

  public int Occupants; // number of occupants

}

The instance variables defined by 

Building

 illustrate the way that instance variables are 

declared in general. The general form for declaring an instance variable is shown here:

access type var-name

;

Here, 

access

 specifies the access; 

type

 specifies the type of variable; and 

var-name

 is the 

variable’s name. Thus, aside from the access specifier, you declare an instance variable in 

the same way that you declare local variables. For 

Building

, the variables are preceded by 

the

public

 access modifier. As explained, this allows them to be accessed by code outside 

of