This print for content only-size & color not accurate 7" X 9-1/4" / casebound / malloy

// A C# class type.

class Calc

{

public int Add(int x, int y)

{ return x + y; }

}

Chapter 5 will begin your examination of building CTS class types with C#; however, Table 1-1

documents a number of characteristics pertaining to class types.

Table 1-1.

CTS Class Characteristics

Class Characteristic

Meaning in Life

Is the class “sealed” or not?

Sealed classes cannot function as a base class to other

classes.

Does the class implement any interfaces?

An interface is a collection of abstract members that

provide a contract between the object and object user.

The CTS allows a class or structure to implement any

number of interfaces.

Is the class abstract or concrete?

Abstract classes cannot be directly created, but are

intended to define common behaviors for derived

types. Concrete classes can be created directly.

What is the “visibility” of this class?

Each class must be configured with a visibility

attribute. Basically, this trait defines whether the class

may be used by external assemblies or only from

within the defining assembly.

C H A P T E R   1  

■

T H E   P H I L O S O P H Y   O F   . N E T

17

8849CH01.qxd  10/1/07  10:30 AM  Page 17

---