Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

Fine-Tuning Classes

In Lesson 24 you learned how to build constructors and destructors, special methods that

execute when an object is created or destroyed. In this lesson you learn about other special

methods you can give a class. You learn how to overload and override class methods.

OVERLOADING METHODS

Lesson 24 mentioned that you can give a class any number of constructors as long as they have

different parameter lists. For example, it’s common to give a class a parameterless constructor

that takes no parameters and one or more other constructors that take parameters.

Making multiple methods with the same name but different parameter lists is called overloading.

C# uses the parameter list to decide which version to use when you invoke the method.

For example, suppose you’re building a course assignment application and you have built

Student, Course, and Instructor classes. You could give the Student class two versions of

the

Enroll method, one that takes as a parameter the name of the class in which the student

should be enrolled and a second that takes a

Course object as a parameter.

You could give the

Instructor class similar versions of the Teach method to make the

instructor teach a class by name or

Course object.

Finally, you could give the

Course class different Report methods that:

Display a report in a dialog if there are no parameters

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Append a report to the end of a file if ...