- 4.1 Introduction
- 4.2 Classes, Objects, Methods, Properties and Instance Variables
- 4.3 Declaring a Class with a Method and Instantiating an Object of a Class
- 4.4 Declaring a Method with a Parameter
- 4.5 Instance Variables and Properties
- 4.6 UML Class Diagram with a Property
- 4.7 Software Engineering with Properties and set and get Accessors
- 4.8 Auto-Implemented Properties
- 4.9 Value Types vs. Reference Types
- 4.10 Initializing Objects with Constructors
- 4.11 Floating-Point Numbers and Type decimal
- 4.12 Wrap-Up
- Summary
- Terminology
- Self-Review Exercises
- Answers to Self-Review Exercises
- Exercises
- Making a Difference Exercises
This chapter is from the book
This chapter is from the book
This chapter is from the book
4.12 Wrap-Up
In this chapter, you learned the basic object-oriented concepts of classes, objects, methods, instance variables and properties—these will be used in most substantial C# applications you create. You learned how to declare instance variables of a class to maintain data for each object of the class, how to declare methods that operate on that data, and how to declare properties to obtain and set that data. We demonstrated how to call a method to tell it to perform its task and how to pass information to methods as arguments. We discussed the difference between a local variable of a method and an instance variable of a class and that only instance variables are initialized automatically. We discussed the difference between a value type and a reference type. You learned how to create auto-implemented properties. You also learned how to use a class's constructor to specify the initial values for an object's instance variables. We discussed some of the differences between value types and reference types. You learned about the value types float, double and decimal for storing real numbers.
We showed how the UML can be used to create class diagrams that model the constructors, methods, properties and attributes of classes. You learned the value of declaring instance variables private and using public properties to manipulate them. For example, we demonstrated how set accessors in properties can be used to validate an object's data and ensure that the object is maintained in a consistent state. In the next chapter we begin our introduction to control statements, which specify the order in which an application's actions are performed. You'll use these in your methods to specify how they should perform their tasks.