From 98b08a890ea852a40fae4b9cc3f697a67825b570 Mon Sep 17 00:00:00 2001 From: Nick Date: Wed, 23 Jun 2021 21:15:32 -0400 Subject: [PATCH] Answers in the read me --- README.md | 77 +++++++++++++++++++++++++--------------------- TicketMachine.java | 6 ++-- bluej.pkg | 60 +++++++++++++++++++++++------------- package.bluej | 60 +++++++++++++++++++++++------------- 4 files changed, 121 insertions(+), 82 deletions(-) diff --git a/README.md b/README.md index ee11f2c..8e177b7 100644 --- a/README.md +++ b/README.md @@ -18,67 +18,74 @@ Work through all these exercises. You edit this file with your answers for these * Use `getPrice` method to view the value of the price of the tickets that was set when this object was created. * Use `insertMoney` method to simulate inserting an amount of money into the machine. * Use `getBalance` to check that the machine has a record of the amount inserted. - * You can insert several separate amounts of money into the machine, just like you might insert multiple coins or notes into a real machine. Try inserting the exact amount required for a ticket. As this is a simple machine, a ticket will not be issued automatically, so once you have inserted enough money, call the `printTicket` method. A facsimile ticket should be printed in the BlueJ terminal window. + * You can insert several separate amounts of money into the machine, just like you might insert multiple coins or notes into a real machine. Try inserting the exact amount required for a ticket. As this is a simple machine, a ticket will not be issued automatically, so once you have inserted enough money, call the `printTicket` method. A facsimile ticket should be printed in the BlueJ terminal window. ### 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? - * What happens if you insert too much money into the machine – do you receive any refund? - * What happens if you do not insert enough and then try to print a ticket? + * Do you notice anything strange about the machine’s behavior? -Balance is always zero + * What happens if you insert too much money into the machine – do you receive any refund? - No. + * What happens if you do not insert enough and then try to print a ticket? - Still get a 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. - +- I did ### Exercise 2.5 * Create another ticket machine for tickets of a different price. - * Buy a ticket from that machine. - * Does the printed ticket look different? + * Buy a ticket from that machine. + * Does the printed ticket look different. + -Yes. ### 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 void Student(){ + public class void LabClass(){ + + } +} + ### Exercise 2.7 Does it matter whether we write
`public class TicketMachine`
or
`class public TicketMachine`
in the outer wrapper of a class? - +--- Yes it does, `public class TicketMachine` * 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? - * What error message do you get when you now press the compile button? - * Do you think this message clearly explains what is wrong? + * Do you notice a change in the class diagram? -no + * What error message do you get when you now press the compile button? + * Do you think this message clearly explains what is wrong? ### Exercise 2.8 * Check whether or not it is possible to leave out the word `public` from the outer wrapper of the `TicketMachine` class. - +-it is not possible ### 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. - + * 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. +-where can you find the code 2.1?? ### Exercise 2.10 * Do you notice any features of the constructor that make it significantly different from the other methods of the class? - +-No I do not ### 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; a private-Integer +private Student representative; a private-Object +private Server host; a private-Host ``` ### Exercise 2.12 * What are the names of the following fields? ```java -private boolean alive; -private Person tutor; -private Game game; +private boolean alive; -boolean +private Person tutor; -Object +private Game game; -Object ``` ### Exercise 2.13 @@ -87,36 +94,36 @@ In the following field declaration from the TicketMachine class
```java private int price; ``` -does it matter which order the three words appear in? +does it matter which order the three words appear in? -Yes it does * 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? - * 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! + * Does the appearance of the class diagram after each change give you a clue as to whether or not other orderings are +possible? -Yes, after compile it won't work. + * Check by pressing the compile button to see if there is an error message. - there was + * 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? -* Once again, experiment via the editor. +* Is it always necessary to have a semicolon at the end of a field declaration? -Yes +* Once again, experiment via the editor. -Doesn't compile because the line technically doesnt end * The rule you will learn here is an important one, so be sure to remember it. - +-I will. ### Exercise 2.15 * Write in full the declaration for a field of type `int` whose name is `status`. - + int status; ### Exercise 2.16 * To what class does the following constructor belong? ``` public Student(String name) ``` - +-name ### Exercise 2.17 * How many parameters does the following constructor have and what are their types? ``` public Book(String title, double price) ``` - + String** title, double** price (the ** signify the types) ### Exercise 2.18 -* Can you guess what types some of the `Book` class’s fields might be? +* Can you guess what types some of the `Book` class’s fields might be? * Can you assume anything about the names of its fields? READ upto and INCLUDING section 2.15 of this chapter. diff --git a/TicketMachine.java b/TicketMachine.java index 630c4ea..31b490a 100644 --- a/TicketMachine.java +++ b/TicketMachine.java @@ -28,9 +28,9 @@ public class TicketMachine public TicketMachine(Integer ticketCost) { price = ticketCost; - balance = 0; - total = 0; - ticketNumber = 0; + balance = 500; + total = 500; + ticketNumber = 500; } /** diff --git a/bluej.pkg b/bluej.pkg index bf25784..3726303 100644 --- a/bluej.pkg +++ b/bluej.pkg @@ -1,32 +1,48 @@ #BlueJ package file -editor.fx.0.height=722 -editor.fx.0.width=800 -editor.fx.0.x=709 -editor.fx.0.y=113 +dependency1.from=TicketMachineTest +dependency1.to=TicketMachine +dependency1.type=UsesDependency +editor.fx.0.height=715 +editor.fx.0.width=790 +editor.fx.0.x=464 +editor.fx.0.y=23 objectbench.height=101 -objectbench.width=461 +objectbench.width=438 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=0.837593984962406 +package.editor.height=550 +package.editor.width=344 +package.editor.x=0 +package.editor.y=35 +package.frame.height=723 +package.frame.width=462 +package.numDependencies=1 +package.numTargets=3 package.showExtends=true package.showUses=true project.charset=UTF-8 -readme.height=58 +readme.height=60 readme.name=@README -readme.width=47 +readme.width=48 readme.x=10 readme.y=10 -target1.height=50 -target1.name=TicketMachine +target1.height=70 +target1.name=TicketMachineTest target1.showInterface=false -target1.type=ClassTarget -target1.width=120 -target1.x=80 -target1.y=50 +target1.type=UnitTestTargetJunit4 +target1.width=130 +target1.x=160 +target1.y=110 +target2.height=50 +target2.name=TicketMachine +target2.showInterface=false +target2.type=ClassTarget +target2.width=120 +target2.x=80 +target2.y=50 +target3.height=70 +target3.name=README.md +target3.type=TextTarget +target3.width=120 +target3.x=10 +target3.y=110 diff --git a/package.bluej b/package.bluej index bf25784..3726303 100644 --- a/package.bluej +++ b/package.bluej @@ -1,32 +1,48 @@ #BlueJ package file -editor.fx.0.height=722 -editor.fx.0.width=800 -editor.fx.0.x=709 -editor.fx.0.y=113 +dependency1.from=TicketMachineTest +dependency1.to=TicketMachine +dependency1.type=UsesDependency +editor.fx.0.height=715 +editor.fx.0.width=790 +editor.fx.0.x=464 +editor.fx.0.y=23 objectbench.height=101 -objectbench.width=461 +objectbench.width=438 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=0.837593984962406 +package.editor.height=550 +package.editor.width=344 +package.editor.x=0 +package.editor.y=35 +package.frame.height=723 +package.frame.width=462 +package.numDependencies=1 +package.numTargets=3 package.showExtends=true package.showUses=true project.charset=UTF-8 -readme.height=58 +readme.height=60 readme.name=@README -readme.width=47 +readme.width=48 readme.x=10 readme.y=10 -target1.height=50 -target1.name=TicketMachine +target1.height=70 +target1.name=TicketMachineTest target1.showInterface=false -target1.type=ClassTarget -target1.width=120 -target1.x=80 -target1.y=50 +target1.type=UnitTestTargetJunit4 +target1.width=130 +target1.x=160 +target1.y=110 +target2.height=50 +target2.name=TicketMachine +target2.showInterface=false +target2.type=ClassTarget +target2.width=120 +target2.x=80 +target2.y=50 +target3.height=70 +target3.name=README.md +target3.type=TextTarget +target3.width=120 +target3.x=10 +target3.y=110