From 5580c32bc0f37ac83bed4e569ba2197160a4747c Mon Sep 17 00:00:00 2001 From: michkin32 <41129043+michkin32@users.noreply.github.com> Date: Wed, 16 Oct 2019 21:04:22 -0400 Subject: [PATCH 1/3] Update README.md --- README.md | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/README.md b/README.md index 4f153b0..4c2ee35 100644 --- a/README.md +++ b/README.md @@ -17,13 +17,13 @@ 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? - +its 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? + * What happens if you insert too much money into the machine – do you receive any refund? nope the balance changes to 0 + * What happens if you do not insert enough and then try to print a ticket? It still prints 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. @@ -31,10 +31,18 @@ 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? - + yup ### 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 Student +{ +} + ### Exercise 2.7 Does it matter whether we write
`public class TicketMachine`
@@ -43,17 +51,23 @@ or
in the outer wrapper of a class? * 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? yup + * What error message do you get when you now press the compile button? expected + * Do you think this message clearly explains what is wrong? kinda ### 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 posssible but i dont know why there is no syntax error ### 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. + fields: 1. price + 2. balance + 3. total + 4. ticketNumber + Constructers: + 1. ### Exercise 2.10 * Do you notice any features of the constructor that make it significantly different from the other methods of the class? From 762da9a387fb9553abafac7255780e8700316ec8 Mon Sep 17 00:00:00 2001 From: michkin32 <41129043+michkin32@users.noreply.github.com> Date: Thu, 17 Oct 2019 07:25:18 -0400 Subject: [PATCH 2/3] Update README.md Mostly answered --- README.md | 43 +++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-) diff --git a/README.md b/README.md index 4c2ee35..1f0dc44 100644 --- a/README.md +++ b/README.md @@ -21,7 +21,7 @@ its 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? nope the balance changes to 0 + * What happens if you insert too much money into the machine – do you receive any refund? It takes all your money and gives no change or refund * What happens if you do not insert enough and then try to print a ticket? It still prints a ticket ### Exercise 2.4 @@ -39,7 +39,7 @@ public class Student { } -public class Student +public class LabClass { } @@ -48,7 +48,7 @@ Does it matter whether we write
`public class TicketMachine`
or
`class public TicketMachine`
-in the outer wrapper of a class? +in the outer wrapper of a class? yes, we get a compiler error if it is in the wrong order. * 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? yup @@ -66,28 +66,35 @@ it is posssible but i dont know why there is no syntax error 2. balance 3. total 4. ticketNumber - Constructers: - 1. + constructers: + 1. TicketMachine(Integer ticketCost) + methods:1. calculateTotal() + 2. getBalance() + 3. getPrice() + 4. getTicketNumber() + 5. incrementTicketNumber() + 6. insertMoney() + 7. printTicket() ### Exercise 2.10 * Do you notice any features of the constructor that make it significantly different from the other methods of the class? - +It has the same name as the class. It doesn't return a value ### 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; int +private Student representative; String +private Server host; String ``` ### 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 @@ -96,30 +103,30 @@ 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? yup if you switch it, it causes a symbol error * 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 * 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? +* Is it always necessary to have a semicolon at the end of a field declaration? yes * 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`. - +private int status; ### Exercise 2.16 -* To what class does the following constructor belong? +* To what class does the following constructor belong? Student ``` public Student(String name) ``` ### Exercise 2.17 -* How many parameters does the following constructor have and what are their types? +* How many parameters does the following constructor have and what are their types? 2 (String, Double) ``` public Book(String title, double price) ``` From e3c151ba00ad299eb6c56838303d5f95696e5619 Mon Sep 17 00:00:00 2001 From: michkin32 <41129043+michkin32@users.noreply.github.com> Date: Thu, 17 Oct 2019 09:28:42 -0400 Subject: [PATCH 3/3] Update README.md --- README.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 1f0dc44..c368fe0 100644 --- a/README.md +++ b/README.md @@ -132,7 +132,7 @@ public Book(String title, double price) ``` ### Exercise 2.18 -* Can you guess what types some of the `Book` class’s fields might be? -* Can you assume anything about the names of its fields? +* Can you guess what types some of the `Book` class’s fields might be? String, int, double +* Can you assume anything about the names of its fields? I can assume that there might be a pages field that is an int, and a author field that is a String. READ upto and INCLUDING section 2.15 of this chapter.