VB book

http://www.barnesandnoble.com/w/an-introduction-to-visual-basic-50-gary-b-shelly/1002550540?ean=9780789527776

VP project 1

VB PP 1.48-1.50 1-4

Matthew Walker

3A 2/7/13

A.

1. T

                2. F

                3. F

                4. T

                5. T

                6.

                7.

                8.

                9.

                10.

B.

                1.

                2.

                3.

                4.

                5.

                6.

                7.

                8.

                9.

                10.

C.

                1. tool box

                2. form

                3.

                4.

                5.

                6.

D.

                1. label

                2. textbox

                3. command button

                4. V scroll bar

                5. Save project

                6. cut

                7. copy

                8. paste

                9. undo

                10. redo

                11. start

                12. end

AP GOV WS Site

http://govhsapgov.wikispaces.com/study_guide_home

Lesson 21 Excercise

Lesson 21 Exercise

Matthew Walker

Balcar 3A 1/30/13

1. The classes that convert primitives to objects are called Wrapper classes.

2. Name the four primitive data types with which wrapper classes primarily deal.

Integer, Double, Boolean,Character

3. Write code that will convert double dx into a wrapper class object. Call the object dd.

   

4. Write code that will produce a Boolean type wrapper object called bj (“wrap” a true

inside it).

    boolean bj = bObj.booleanValue( 5<7);

5. Write code that will convert the integer ip into an Integer wrapper class object. Call the

object ozzie.

6. Assume you have the object Character cw. Write code to convert this to a primitive

character.

7. Assume you have Double objects d1 and d2. Show how you would multiply the values

stored in these objects and then store the answer in primitive double dd.

8. Assume you have Integer objects i1 and i2. Show how you would add the values stored

in these objects and then store the answer in a third Integer object called i3.

9. Write code that will extract the boolean wrapped in the Boolean wnOh and test it with an

if statement.

if ( )

10. Convert the object jj (of type Double) into a primitive float called ff.

11. Convert the object pk (of type Double) into a primitive int called gurg. What is the

danger of doing this?

12. What is the primary purpose of wrapper classes?

Lesson 20 Excercise

Lesson 20 Exercise

Matthew Walker

Balcar 3A 1/30/13

1. At any time after several TvShow objects have been instantiated, how would you find out

how many shows were instantiated? (Don’t use an object to do this.)

2. Would the code inside the numberOfShows method still be correct if numberOfShows

were non-static? If not, why?

3. Suppose the code inside the numberOfShows method is replaced with the following line:

return y;

Is this legal? If not, why?

4. Write code that will print the data member actor2. Do this without instantiating any

objects.

5. Is the following code legal? If not, why?

TvShow.setActor1(“Jimmy Stewart”);

6. Create an instance of TvShow called chrs (pass in the String “Cheers”) and use it to

access and print the class variable numShows.

7. Give the output of the following:

System.out.println(TvShow.x);

TvShow chrs = new TvShow(“Cheers”);

System.out.println(TvShow.x);

System.out.println(chrs.x);

TvShow hc = new TvShow(“History Channel”);

hc.x = 160;

System.out.println(TvShow.x);

System.out.println(hc.x);

8. Is the following a legal declaration of a class variable? If not, why?

static public char ch = ‘K’;

9. Write code that will cause the variable zxb to be a static state variable. The variable zxb is

a double.

10. Write code that will cause sn to be a constant static class member. The constant sn should

be initialized as an empty String.

11. What is the significance of the word Math when we use Math.pow(3.2, 4.001)?

Math is the class variable

12. Class variables are also called Static State variables.

13. Assuming that the appropriate static import has been done, rewrite the following code

without using the class name of the static methods.

double xop = Math.pow(Math.sqrt(x - zv), 3.1);

14. What are the two primary reasons for using the key-word, static?

            1. you can call a method without creating an object

2. they are shared by all objects