Knowledge Check

1. If the TextLength property of a TextBox object is less than 1, what does that tell you?

2. What properly is used to ensure that the user has entered all digits in a MaskedTextBox object?

3. What properly can you use to specify the sequence of objects that will be selected when the user presses the tab key?

4. What are the names of the three tiers in a three-tiered program structure? What occurs in each of the three tiers?

5. In a three-tiered program structure, which tiers are allowed to communicate with each other?

6. Identify the three steps to create a new class in a Visual Basic program.

7. Write the code to instantiate the objEmployee object based on the Employee class.

8. When is a class constructor executed?

9. Write the code to instantiate the objVehicle object based on the Vehicle class and to pass the following values to the object: Color, Model, Engine. Write the New statement in the Vehicle class.

10. Write a statement to call the ComputeDiscount procedure in the objDiscountItem object.

11. Explain the benefits of using separate classes in a program.

12. Complete the following sentence: Inheritance allows one class to inherit ____________ and ______________ from another class.

13. Describe the difference between a base class and a subclass when using inheritance.

14. What entry must be included in the Class statement of a subclass? 15. What is the first statement that must be coded in a subclass constructor?

16. What is an overridable procedure? Why is it used?

17. In a class, can an attribute be referenced that is not defined in the class? How is this attribute reference resolved?

18. What is a comma-delimited text file?

19. When an IO.StreamWriter is created, what does the IO.File.AppendText entry mean?

20. What is the difference between the Write procedure and the WriteLine procedure in the IO.StreamWriter class?