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44 changes: 35 additions & 9 deletions README.md
Original file line number Diff line number Diff line change
Expand Up @@ -17,12 +17,16 @@ Work through all these exercises. You edit this file with your answers for these

### Exercise 2.2
* What value is returned if you check the machine’s balance after it has printed a ticket?
-0

### Exercise 2.3
* Experiment with inserting different amounts of money before printing tickets.
* Do you notice anything strange about the machine’s behavior?
* Do you notice anything strange about the machine’s behavior?
- Yes, It just accumulates the amount of money inserted.
* What happens if you insert too much money into the machine – do you receive any refund?
- No refund or error message
* What happens if you do not insert enough and then try to print a ticket?
- It will still print ticket.

### Exercise 2.4
* Try to obtain a good understanding of a ticket machine’s behavior by interacting with it on the object bench before we start looking at how the `TicketMachine` class is implemented in the next section.
Expand All @@ -31,49 +35,61 @@ Work through all these exercises. You edit this file with your answers for these
* Create another ticket machine for tickets of a different price.
* Buy a ticket from that machine.
* Does the printed ticket look different?
- Looks the same, the total keeps accumulating.

### Exercise 2.6
* Write out what you think the outer wrappers of the `Student` and `LabClass` classes might look like – do not worry about the inner part.
- public class Student
- public class LabClass

### Exercise 2.7
Does it matter whether we write<br>
`public class TicketMachine`<br>
or<br>
`class public TicketMachine`<br>
in the outer wrapper of a class?
-Yes, Must be public and then class; otherwise there is an error (identifier)

* Edit the source of the `TicketMachine` class to make the change and then close the editor window.
* Do you notice a change in the class diagram?
* Do you notice a change in the class diagram?
- Yes, cannot compile or run.
* What error message do you get when you now press the compile button?
- Illegal start of expression.
* Do you think this message clearly explains what is wrong?
No, does not let us know that is not possible.

### Exercise 2.8
* Check whether or not it is possible to leave out the word `public` from the outer wrapper of the `TicketMachine` class.
-Its defaults to public, you could leave it out.

### Exercise 2.9
* From your earlier experimentation with the ticket machine objects within BlueJ you can probably remember the names of some of the methods – `printTicket`, for instance.
* Look at the class definition in Code 2.1 and use this knowledge, along with the additional information about ordering we have given you, to try to make a list of the names of the fields, constructors, and methods in the `TicketMachine` class.
* Hint: There is only one constructor in the class.
- Methods: getPrice, getTicketNumber, getBalance, insertMoney, calculateTotal, incrementTicketNumber, printTicket
- Fields: price, balance, total ticketNumber
- Constructor: TicketMachine testTicketMachine = new TicketMachine.

### Exercise 2.10
* Do you notice any features of the constructor that make it significantly different from the other methods of the class?
- Its a test for the ticket machine to see if it runs properly.

### Exercise 2.11
* What do you think is the type of each of the following fields?

```java
private int count;
private Student representative;
private Server host;
private int count; - Integer
private Student representative; - Class
private Server host; - Class
```

### Exercise 2.12
* What are the names of the following fields?

```java
private boolean alive;
private Person tutor;
private Game game;
private boolean alive; - alive
private Person tutor; - tutor
private Game game; - game
```
### Exercise 2.13

Expand All @@ -83,35 +99,45 @@ In the following field declaration from the TicketMachine class<br>
private int price;
```
does it matter which order the three words appear in?
- Yes, you need to define them or Java won't be able to read them.

* Edit the `TicketMachine` class to try different orderings. After each change, close the editor.
* Does the appearance of the class diagram after each change give you a clue as to whether or not other orderings are
possible?
possible?
- Yes, its shows an error.
* Check by pressing the compile button to see if there is an error message.
* Make sure that you reinstantiate the original version after your experiments!

### Exercise 2.14
* Is it always necessary to have a semicolon at the end of a field declaration?
- Yes, this will let you the statement is done.
* Once again, experiment via the editor.
* The rule you will learn here is an important one, so be sure to remember it.


### Exercise 2.15
* Write in full the declaration for a field of type `int` whose name is `status`.
- int I = status

### Exercise 2.16
* To what class does the following constructor belong?
```
public Student(String name)
```
- Student

### Exercise 2.17
* How many parameters does the following constructor have and what are their types?
```
public Book(String title, double price)
```
-2 String title and double price

### Exercise 2.18
* Can you guess what types some of the `Book` class’s fields might be?
- String Character char

* Can you assume anything about the names of its fields?
-Book has words so it may print out lines of characters.

READ upto and INCLUDING section 2.15 of this chapter.
6 changes: 6 additions & 0 deletions TicketMachine.java
Original file line number Diff line number Diff line change
Expand Up @@ -95,4 +95,10 @@ public String printTicket()

return "Ticket price: " + price + " cents. " + "Your total is " + total + ".";
}


public static void main(String[] args){

}

}
46 changes: 28 additions & 18 deletions bluej.pkg
Original file line number Diff line number Diff line change
@@ -1,20 +1,23 @@
#BlueJ package file
editor.fx.0.height=722
dependency1.from=TicketMachineTest
dependency1.to=TicketMachine
dependency1.type=UsesDependency
editor.fx.0.height=713
editor.fx.0.width=800
editor.fx.0.x=709
editor.fx.0.y=113
editor.fx.0.x=240
editor.fx.0.y=23
objectbench.height=101
objectbench.width=461
objectbench.width=604
package.divider.horizontal=0.6
package.divider.vertical=0.8007380073800738
package.editor.height=427
package.editor.width=674
package.editor.x=1067
package.editor.y=119
package.frame.height=600
package.frame.width=800
package.numDependencies=0
package.numTargets=1
package.divider.vertical=0.6447368421052632
package.editor.height=189
package.editor.width=502
package.editor.x=0
package.editor.y=373
package.frame.height=362
package.frame.width=628
package.numDependencies=1
package.numTargets=2
package.showExtends=true
package.showUses=true
project.charset=UTF-8
Expand All @@ -24,9 +27,16 @@ readme.width=47
readme.x=10
readme.y=10
target1.height=50
target1.name=TicketMachine
target1.name=TicketMachineTest
target1.showInterface=false
target1.type=ClassTarget
target1.width=120
target1.x=80
target1.y=50
target1.type=UnitTestTargetJunit4
target1.width=140
target1.x=10
target1.y=110
target2.height=50
target2.name=TicketMachine
target2.showInterface=false
target2.type=ClassTarget
target2.width=120
target2.x=80
target2.y=50
46 changes: 28 additions & 18 deletions package.bluej
Original file line number Diff line number Diff line change
@@ -1,20 +1,23 @@
#BlueJ package file
editor.fx.0.height=722
dependency1.from=TicketMachineTest
dependency1.to=TicketMachine
dependency1.type=UsesDependency
editor.fx.0.height=713
editor.fx.0.width=800
editor.fx.0.x=709
editor.fx.0.y=113
editor.fx.0.x=240
editor.fx.0.y=23
objectbench.height=101
objectbench.width=461
objectbench.width=604
package.divider.horizontal=0.6
package.divider.vertical=0.8007380073800738
package.editor.height=427
package.editor.width=674
package.editor.x=1067
package.editor.y=119
package.frame.height=600
package.frame.width=800
package.numDependencies=0
package.numTargets=1
package.divider.vertical=0.6447368421052632
package.editor.height=189
package.editor.width=502
package.editor.x=0
package.editor.y=373
package.frame.height=362
package.frame.width=628
package.numDependencies=1
package.numTargets=2
package.showExtends=true
package.showUses=true
project.charset=UTF-8
Expand All @@ -24,9 +27,16 @@ readme.width=47
readme.x=10
readme.y=10
target1.height=50
target1.name=TicketMachine
target1.name=TicketMachineTest
target1.showInterface=false
target1.type=ClassTarget
target1.width=120
target1.x=80
target1.y=50
target1.type=UnitTestTargetJunit4
target1.width=140
target1.x=10
target1.y=110
target2.height=50
target2.name=TicketMachine
target2.showInterface=false
target2.type=ClassTarget
target2.width=120
target2.x=80
target2.y=50