From 1e8f20a410355a4c96308216b064ed9c8642343e Mon Sep 17 00:00:00 2001 From: Laura Date: Thu, 24 Jun 2021 23:13:55 -0400 Subject: [PATCH] morecode --- README.md | 65 ++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 45 insertions(+), 20 deletions(-) diff --git a/README.md b/README.md index ee11f2c..07b0497 100644 --- a/README.md +++ b/README.md @@ -18,27 +18,38 @@ 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? +* the balance would always be zero +* +* ### 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? + * the print ticket method dosent check if enough money has been inserted + * + * What happens if you insert too much money into the machine – do you receive any refund? + * print thicket always recets the balance to zero, even if the amount is higher + * + * What happens if you do not insert enough and then try to print a ticket? + * you can still create with negative numbers + * ### 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. ### 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 student ### Exercise 2.7 Does it matter whether we write
@@ -47,18 +58,28 @@ or
`class public TicketMachine`
in the outer wrapper of a class? +yes + + * 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? + * What error message do you get when you now press the compile button? + * identifier expected + * + * Do you think this message clearly explains what is wrong? + * no but is shows where the problem is + * ### 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 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. + * yes it is posible + * ### Exercise 2.10 * Do you notice any features of the constructor that make it significantly different from the other methods of the class? @@ -67,18 +88,18 @@ in the outer wrapper of a class? * 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; Student +private Server host; Server ``` ### 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 @@ -89,28 +110,32 @@ private int price; ``` does it matter which order the three words appear in? * 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 + * 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! + * 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 * 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? +* Student ``` public Student(String name) ``` ### Exercise 2.17 * How many parameters does the following constructor have and what are their types? +* 2, Sting and double ``` public Book(String title, double price) ```