Thread: java balloon project

hello need help writing this program
don't really know where to begin

I. The Assignment

This assignment is to write a “test” class (aka: a “driver” class or “client code”) that uses the class Balloon.java, available on the class web page.

To use the Balloon class, download it and store it in the src folder of your NetBeans project. Make sure you save it as Balloon.java.

The best way to learn how to use the Balloon class – or any other Java class, for that matter - is to consult the documentation, Balloon.html (online). You can also read the javadoc comments that appear just above the class heading and above each method heading, which explain what each method does, what the method’s parameters are, and what value – if any - is returned by the method. The html “help” pages are generated from these comments.

Don’t worry if you don’t understand the code. It will all be covered later. It is not necessary to know how a method works as long as you know what it does and how to call it.

 Review declaring variables, creating objects, calling methods that return a value vs. “void” methods, and accessor and mutator methods before beginning.

To receive credit for this assignment, you must not modify the Balloon class in any way!


II. Your BalloonTester Class

Your BalloonTester class will have only a single method – main – and will perform each of the following operations, in the exact order listed below. Each operation may be done in one or two statements. Make sure you follow directions faithfully, and note that if you have done step 3, you can copy and paste it to do steps 6, 9, and 12.

1. Create a Balloon object with a name of your own choosing and an altitude of 100 meters.

2. Create a second Balloon object with a name of your own choosing, and specify an initial altitude of -100 meters.

3. Call the accessor methods of the Balloon class to get the name and altitude of each Balloon object. Print the data, one object per line.

4. Make the object you created in step 1 ascend to an altitude of 250 meters.

5. Call the adjustAltitude method to increase the altitude of the object you created in step 2 by 200 meters.

6. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

7. Call the adjustAltitude method to decrease the altitude of the object you created in step 1 by 100 meters.

8. Make the object you created in step 2 descend to the same altitude as the other object.

To get credit for step 8., the statement(s) you write must always work, regardless of the actual altitude of the second object. It cannot depend on you knowing the altitude of the second object, but must utilize the fact that the object knows its own altitude. In other words, if you use a literal in any way to set the altitude, it is not correct.

9. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

10. Move the object you created in step 1 to an altitude that is three times its current altitude. As in step 8, the statement(s) you write must work for any altitude and may not depend on you “figuring out” the new altitude beforehand.

11. Attempt to move the object you created in step 2 to an altitude that is 200 meters below its current altitude.

12. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

I. The Assignment

This assignment is to write a “test” class (aka: a “driver” class or “client code”) that uses the class Balloon.java, available on the class web page.

To use the Balloon class, download it and store it in the src folder of your NetBeans project. Make sure you save it as Balloon.java.

The best way to learn how to use the Balloon class – or any other Java class, for that matter - is to consult the documentation, Balloon.html (online). You can also read the javadoc comments that appear just above the class heading and above each method heading, which explain what each method does, what the method’s parameters are, and what value – if any - is returned by the method. The html “help” pages are generated from these comments.

Don’t worry if you don’t understand the code. It will all be covered later. It is not necessary to know how a method works as long as you know what it does and how to call it.

 Review declaring variables, creating objects, calling methods that return a value vs. “void” methods, and accessor and mutator methods before beginning.

To receive credit for this assignment, you must not modify the Balloon class in any way!


II. Your BalloonTester Class

Your BalloonTester class will have only a single method – main – and will perform each of the following operations, in the exact order listed below. Each operation may be done in one or two statements. Make sure you follow directions faithfully, and note that if you have done step 3, you can copy and paste it to do steps 6, 9, and 12.

1. Create a Balloon object with a name of your own choosing and an altitude of 100 meters.

2. Create a second Balloon object with a name of your own choosing, and specify an initial altitude of -100 meters.

3. Call the accessor methods of the Balloon class to get the name and altitude of each Balloon object. Print the data, one object per line.

4. Make the object you created in step 1 ascend to an altitude of 250 meters.

5. Call the adjustAltitude method to increase the altitude of the object you created in step 2 by 200 meters.

6. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

7. Call the adjustAltitude method to decrease the altitude of the object you created in step 1 by 100 meters.

8. Make the object you created in step 2 descend to the same altitude as the other object.

To get credit for step 8., the statement(s) you write must always work, regardless of the actual altitude of the second object. It cannot depend on you knowing the altitude of the second object, but must utilize the fact that the object knows its own altitude. In other words, if you use a literal in any way to set the altitude, it is not correct.

9. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

10. Move the object you created in step 1 to an altitude that is three times its current altitude. As in step 8, the statement(s) you write must work for any altitude and may not depend on you “figuring out” the new altitude beforehand.

11. Attempt to move the object you created in step 2 to an altitude that is 200 meters below its current altitude.

12. Call the accessor methods of the Balloon class to get the name and altitude of each object. Print the data, one object per line.

Please don't post the same topic multiple times.

Waddya mean you don't know where to start? It tells you exactly where to start and what to do step by step. What don't you understand?

Duplicate.

how do I create the balloon. I am new to this site as well as programming apologize for duplicate post. also not sure how to set up the main class

That seems pretty obvious. Do you know how to create objects and call their member functions?

Go through some of the stuff here for further details.

I am just looking for a starting point I don't see the need to pass judgement. But whatever this was a waste of time.

srozo22, I'm sorry if you're feeling offended, but you asked a very broad question and didn't show what things, if any, you tried. I know that some teachers are worse than others, but I highly doubt your teacher would have assigned this project if he didn't teach you the basics of classes. The questions in my post were meant to assess what you know and prompt you to think about the project so you would know where to begin.

We can't just tell you the answer, because aside from ethical issues of academic dishonesty, doing so would not help you learn. You would be completely sunk on your next assignment which would inevitably be more difficult. The best way to learn is by practice, and the best way to teach is by asking the right questions to evoke a gauge of knowledge from the student.

The way to start, most broadly, is to open up your development program and create a new program.

It sounds like the balloon class was already provided to you, which is good. You should know how to work with classes before designing your own.

Do you know how to declare a new integer?
Do you know how to declare a new instance of a class?
Do you know how to access the member variables in a class once you've declared an instance of it?
Do you know how to access the member functions in a class once you've declared an instance of it?

Yes I know how to. Open the new project and use the existing file provided with the tester class I need to create. I have an issue with the terminology and also creating the new integer or. Balloon and assigning its altitude. The class declarations I am also confused about, and how to literally begin writing the testt class. From there I believe I can access the names and altitudes of the balloons created. My problem as I stated is where to begin in creating the balloon to be more specific.

Originally Posted by srozo22

creating the balloon to be more specific.

Creating objects tutorial

Ok I think the teacher is using some terminology that may be confusing you. It seems that in this context, the "test class" is just the main program. Every program in Java contains at the very least one class. So here I create the "Hello world" class.

public class HelloWorld
{
    public static void main(String[] args)
    {
      System.out.println("Hello world!");
     }
}

That's just the most basic class. You can get more complex and add additional functions and class variables, which is what your teacher did in the balloon class.

As for using the balloon class your teacher provided, the link JPS supplied will help. Just think of classes this way: a class is thing that defines how you create objects. To put it in more concrete terms, think of an apple pie. The pie is the object, the recipe is the class.

Objects are also, essentially, variables. You can do things with them that you can do with primitive variables (like int and double)--pass them to functions, have functions return them. In that vein, you declare them sort of like variables, except you use the "new" keyword followed by the object's name, followed by whatever parameters the constructor requires in parentheses.

Read the link JPS provided. It's pretty good stuff.