Introduction To Classes Test Questions & Answers Ch.10

Starting Out with Visual C#, 5e (Tony Gaddis)

Chapter 10 Introduction to Classes

TRUE/FALSE

1. A class is not an object; it is a description of an object.

2. The class header defines a class's fields, properties, and methods.

3. The name of a class's constructor is the same as the name of the class.

4. A class's constructor header must specify a return type of void.

5. A class's constructor must always use the private access modifier.

6. When a class contains a method that uses the public access modifier, the method can be called from outside the class.

7. When you create an object from a class you use a reference variable to reference that object.

8. Because classes are reference types, objects that are instances of a class are always passed by reference.

9. In code that creates an instance of a class, you access the class object's properties in the same way that you would access public variables.

10. A property is a class member that behaves like a public field.

11. The set accessor is executed any time that a property is read.

12. The get accessor has an implicit parameter called a value.

13. Class fields are almost always declared private in order to protect them from accidental corruption.

14. If you try to pass a property to a ref or an out parameter, an error occurs.

15. To make a property read-only, omit the get accessor for the property.

16. To make a property read-only, omit the set accessor for the property.

17. An error will occur if you try to assign a value to a read-only property.

18. Constructors cannot accept arguments in the same way as other methods.

19. If two methods have the same names and parameter lists, you cannot overload them by just giving them different return types.

20. Constructors cannot be overloaded which means a class can only have one constructor.

21. Objects that are instances of a class cannot be stored in an array.

22. When you want to create a List object, you follow List with the name of a class inside angled brackets, and it specifies that the List can hold only objects of that class type.

23. When designing an object-oriented application, one of your first tasks is to identify the classes you need to create.

24. All of the nouns that appear in a problem description should become classes.

25. Once the classes have been identified in a problem description, the next task is to identify each class's responsibilities.

26. Every form in a Visual C# project is defined by a class.

27. When you have multiple forms in a project, you should give each form a meaningful name that describes its purpose.

28. Once you have added a form to a project, you can place any controls on it and write the necessary event handlers for the controls.

29. You can use the tabs appearing at the top of the Designer window to select different forms or their code to be displayed in the window.

30. Once a form has been created, it cannot be removed from a Visual Studio project.

31. In your application's code, the first step in displaying a form is to create an instance of the form's class.

32. Creating an instance of a form's class also displays the form on the screen.

33. Both instance fields and instance methods are associated with a specific instance of a class and cannot be used until an instance of the class is created.

34. When a value is stored in a static field or static property, it must be stored in an instance of the class.

35. When a field is declared with the static keyword, there is only one copy of the field in memory.

36. If a class is declared as static then all members of the class must be static or a compiler error will occur.

37. When a property is declared as static, the property's value in memory depends on the number of instances of the class that exist.

MULTIPLE CHOICE

1. Each object created from a class is called a(n) __________ of the class.

2. You create a class by writing a(n) __________.

3. The first line of a class declaration is known as the __________.

4. A class's __________ are statements that define the class's fields, properties, and methods.

5. A(n) __________ is a method that is automatically executed when an object is created.

6. Classes are __________ types.

7. By using the __________ access modifier, a class can hide its data from code outside the class.

8. Which of the following statements declares a variable named fox that references an instance of the Animal class?

9. Which of the following statements calls the Jump method of the Animal class using a reference variable named fox?

10. When you call a method and pass a class instance as an argument, the parameter variable becomes a(n) __________ to the object.

11. A __________ is a special type of class member that allows an object to store and retrieve a piece of data.

12. A special set of methods, known as __________, work in conjunction with a private field.

13. The __________ is a method that returns the property's value.

14. In a property definition, the __________ is automatically created by the compiler and its data type is the same as that of the property.

15. When a value is assigned to a property, the property's __________ is executed and the value being assigned is contained in the value parameter.

16. A __________ can be read but it cannot be modified.

17. When a field's value is dependent on other data and the field is not updated when its related data changes, we say the field has become __________.

18. A constructor that accepts arguments is known as a(n) __________.

19. When a method is __________, it means that multiple methods in the same class have the same name but use different types of parameters.

20. The process of matching a method call with the correct version of a method is known as __________.

21. The compiler uses a method's __________ to distinguish it from other methods of the same name.

22. A method's __________ is not part of the signature.

23. If you write a class with no constructor whatsoever, the compiler provides a(n) __________.

24. When you create an array of a class type, each element of the array will be initialized with the value __________ by default.

25. To add an object of a class to a List you use the __________ method.

26. The __________ is the set of real-world objects, parties, and major events related to the problem.

27. Each of the __________ in the description of a problem domain is a potential class.

28. When you have identified the information that a class is responsible for knowing, then you have identified the class's __________.

29. When you have identified the actions that a class is responsible for doing, then you have identified the class's __________.

30. When you add additional forms to a project, you add additional __________ which are stored in their own source code files.

31. When working with multiple forms, use the __________ to change the name of the Form1.cs file to something more meaningful.

32. To add a new form to a project, first click __________ on the Visual Studio menu bar and then select Add Windows Form... from the Project menu.

33. In Visual Studio you can easily switch your view to another form by double-clicking on the form's entry in the __________ window.

34. If you wish to remove a form from a project and delete its file from the disk, first right-click on the form's entry in the Solution Explorer window and click __________ on the pop-up menu.

35. If you wish to remove a form from a project but you don't want to delete its file from the disk, first right-click on the form's entry in the Solution Explorer window and click __________ on the pop-up menu.

36. Suppose a project has a form named SummaryForm. Which of the following statements creates an instance of the SummaryForm class and assigns it to a variable?

37. The __________ method displays a form on the screen and it gives that form the focus.

38. When a __________ form is displayed, no other form in the application can receive the focus until the form is closed.

39. If you want to show a form in modeless fashion, call its __________ method.

40. Static methods operate on __________.

41. Which of the following is the correct way to create a static method named PoundsToKg that converts pounds to kilograms?

42. Which of the following is the correct way to declare a static field named myCount?

43. To access a static property, you use __________.

44. Which of the following statements about static methods is true?