I have stumbled onto a problem with ArrayLists (not sure if nested ArrayList objects would be a more accurate description) ....
As simply put as I can describe it, I have an Inventory class which creates an ArrayList of a Product superclass, which has two subclasses, PerishableProduct and ItemisedProduct.
By default, the program is meant to have a starting inventory, which is why I have added them in the constructor
public class Inventory { private List<Product> products; public Inventory() { addProduct(new Product("Frying pan", 15, 20)); addProduct(new PerishableProduct("Apple", 5.8, 30, 7)); addProduct(new ItemisedProduct("Cereal", 5.8, 0)); // this is where I am having problems. Wanting to add // objects to the ItemisedProduct's ArrayList for cereal. }
Within the ItemisedProduct subclass is yet another ArrayList which is meant to hold serial numbers.
public class ItemisedProduct extends Product { private ArrayList<String> serialNumbers = new ArrayList(); public ItemisedProduct(String name, double price, int qty) { super(name, price, qty)
[Code] .....
My problem is that I do not know how to populate the serialNumbers ArrayList from the Inventory class' constructor. Because technically, quantity is defined by how many serial numbers are created.
I am trying to do this assignment but I can't get the needed output.
Create a program that asks the user how many floating point numbers he wants to give. After this the program asks the numbers, stores them in an array and prints the contents of the array in reverse order.
Program is written to a class called ReverseNumbers.
Example output
How many floating point numbers do you want to type: 5
Type in 1. number: 5,4 Type in 2. number: 6 Type in 3. number: 7,2 Type in 4. number: -5 Type in 5. number: 2
Given numbers in reverse order:
2.0 -5.0 7.2 6.0 5.4
Java Code:
import java.util.Scanner; public class apples { public static void main(String[] args) { Scanner reader = new Scanner(System.in); double[] numbers;
I am new to Java and have read books, the Java docs, and searched the Internet for my problem to no avail. I have an Array of objects that contains strings. How can I get the object's strings to print in a list so that the user can select that object to manipulate its attributes? For example, the user can select "Guitar 1" from a list and manipulate its attributes like tuning it, playing it, etc. I have a class called Instruments and created 10 guitar objects.Here is the code:
Instrument [] guitar = new Instrument[10]; for (int i = 0; i < 10; i++) { guitar[0] = new Instrument("Guitar 1"); guitar[1] = new Instrument("Guitar 2"); guitar[2] = new Instrument("Guitar 3"); guitar[3] = new Instrument("Guitar 4"); guitar[4] = new Instrument("Guitar 5"); guitar[5] = new Instrument("Guitar 6");
I am trying to get this to where I can type in a name and it will search through each object and print back the corresponding object info.
Java Code:
import java.util.Scanner; public class MyPeople { public static void main(String[] args) { Person[] p = new Person[] { new Person("Chris", 26, "Male", "NJ", "Single"), new Person("JoAnna", 23, "Female", "NJ", "Single"), new Person("Dana", 24, "Female", "NJ", "Single"), new Person("Dan", 25, "Male", "NJ", "Single"), new Person("Mike", 31, "Male", "NJ", "Married") };
Task:The main method of the class Things below creates an object called printer deriving from the class PrintingClass and uses that object to print text. Your task is to write the PrintingClass class.
Program to complete: import java.util.Scanner; public class Things { public static void main(String args[]) { String characterString; Scanner reader = new Scanner(System.in); PrintingClass printer = new PrintingClass(); System.out.print("Type in the character string for printing: "); characterString = reader.nextLine(); printer.Print(characterString); } }
// Write the missing class here
Note: In this exercise the solution is part of a conversion unit where many classes have been declared. Because of this the classes are not declared as public using the public attribute.
Example output
Type in the character string for printing: John Doe
John Doe
My Class: class PrintingClass { public void print(){ System.out.println(characterString); } }
The number of Contact that I input is just one when I run the program so the Number of contacts: 1 is correct, but it gives me workbook.Contact@46e5590e instead of printing out all the contacts stored inside the Contact class. Yes I do loop through the ArrayList and I also have a method inside the Contact class, the printNameAndPhone(), which prints out the name as well as the phone number but how do I incorporate the printNameAndPhone() method (located in the Contact class) inside the print() method (located inside the AddressBook class)???
Basically I'm asking how to access all the elements in the ArrayList<Contact> addressBook = new ArrayList<>();??My main class AddressBook
package addressbook; import java.util.Scanner; import java.util.ArrayList; public class AddressBook {
I have a main class AddressBook where I use ArrayList<Contact> addressBook = new ArrayList<>(); to add information such as name and phone numbers in my Contact class. How do I go about accessing all the information (names, and phone numbers) that is stored in my Contact class? What happens when I print it out is it only prints out the last input of name and phone number and not the entire collection of names and phone numbers. How do I print out the contents of ArrayList?
I'm creating a card game assignment... so i have an arraylist called cards that has 20 cards and every card has contains 2 objects, suit and the point Value.
I shuffled the deck, now i want to add half of it to player 1 and the rest of the cards goes to the bot or computer.
how can i add the cards to the player one arraylist and have all the information of the cards?
here is my Deck class code :-
public class Deck { private ArrayList cards; private int size; private ArrayList player1; private ArrayList bot;
[code]....
the problem i have is this one doesn't work
size = cards.size() / 2; for (int i = 0; i < size - 1; i++) { player1.add(cards.get(i)); } for (int s = size; s < cards.size() - 1; s++) { bot.add(cards.get(s)); }
So I'm Half way done with this assignment and all I need to is edit and sort my directory. What I've been trying to do as of now is edit my directory. I've tried to use the set function in the Array List, Iterator List etc but I just don't know how implement them mainly because I keep thinking "how can check which variable in the directory the user wants to change(Name, cost etc etc)?".
Main class
Java Code:
package plantnursery; import java.util.Scanner; import java.util.ArrayList; public class PlantNursery { private ArrayList<Plant> plantDirectory = new ArrayList<>(); private static Scanner read = new Scanner(System.in);
Using JDK7 is there a way to get an object that has got a specific property from the collection? For instance, I might want to seek if there is an Address containg "Tim Carlton" in the ArrayList.
I'm almost finished my Bank Account exercise and I found myself stuck at the last part. Its asking me to add a method that asks the user to input the name of the account into which they want to deposit money, then search the ArrayList for that account. If it is found, the user is asked how much money they wish to deposit.
I already have my deposit method sorted so basically what I need is just searching through the ArrayList by the name variable. I assume its don't by iterating through with some form of for loop.Heres what I have:
import java.util.Scanner; public class BankAccount { private double balance; private String name; public BankAccount(double balance, String name){ this.balance = balance;
[Code]......
And the driver class
import java.util.ArrayList; import java.util.Scanner; public class BankDriver { Scanner scan = new Scanner(System.in); ArrayList<BankAccount> list; public BankDriver(){
I am making a function to search through the whole inventory to see if any of the Lamborghini object has a certain model name such as aventador, diablo, etc....
This is what I have but I figured there's a big mistake when I make it true / false; it's making it going through the list and what's return is the last one instead of saying there's such match in the whole list or not.
public boolean hasCarModel(String modelName){ boolean exist = false; for (Lamborghini lambo : inventory){ String carModelName = lambo.getModelName(); if(carModelName.equalsIgnoreCase(modelName)){
[Code] ....
I figured if I add break; under exist = true; it'll work because as soon as it found one match then it'll turn to true and break out the loop but I don't think this is the best way to do it right?
Scanner in = new Scanner(System.in); ArrayList<rand> selectedRand = new ArrayList<Rand>(); selectedRand.add(new Rand(in.nextLine()));
I have created the most minimal code for creating an array list. I was wondering what the basic syntax of accessing objects methods that are within an Array List. So if I was to trying and get a method such as [.returnValue,] how would this look within a Rand object that is declared in a Array List Since you cannot simply declare a new Rand object and say:
newRandObject.returnValue();
And you must go through the actual slotted portion of the array list. I have searched the web and my text book for an example however none are provided.
package com.practice; public class Car { private String name; //name of the car private String modelName; //Name of the model private int year; //The year car was made in private int speed=0;
[Code] ...
It wont let me copy it into a array is there any solution to this.
I want to get the max volume from a file that I stored in an arraylist but it don't know if this is the way to do it. also I don't know how to print the method in the main method. here is the method that will get the max volume
public Shape3D maxVolume(ArrayList<Shape3D> shapes ){ Shape3D currentMax; int currentMaxIndex = 0; for ( int i = 1; i < shapes.size(); i++)
[Code] ....
This is my shape3D class
public abstract class Shape3D implements Comparable<Shape3D> { private String type; public double radious; public double height;
import java.util.ArrayList; public class LectureRoom{ private String courseName; private String roomNumber; private String Lecturer; private ArrayList <Student> studentList;
[Code] .....
Question:
Given the following BlueJ class diagram
Lecturer class (same with previous lab, no changes needed) Student class (same with previous lab, no changes needed)
LectureRoom (changes occurs here)
1. LectureRoom has roomNumber (e.g. A301), courseName (e.g. Java), lecturer (a reference to a Lecturer object), and studentList (a reference to an ArrayList that stores Student object). 2. LectureRoom has a constructor that receives courseName, roomNumber, and Lecturer. The constructor then sets/assign the courseName, roomNumber and Lecturer. This constructor also creates the studentList arraylist object.
So i have a problem i want to make a menu that allows you to press 1 and then make lets say a Car,
The code would look like
Car car = new Car();
And then add to my list
cars.add(car);
If in my menu the person presses 1 again, will they add another car or will it override it
Also: how can i make a menu that doesnt allow you to press option 5 (something that requires you something that should be registered in other options ), until you registered them?
I am trying to grab a graphical object from an arraylist, and reposition its coordinates on a Jframe when adding it. My program of course deals with strings, and once it sees specific words in my console, some method is called that adds, removes, or otherwises modifies certain objects on screen.
Here I want to say something like move(object[1],xpos,ypos) which will move a certain object from a specified point in the array, and move it to new x and y positions on the JFrame. I use a different class that extends a graphics program, so when I say add(something,x,y) it draws the object onscreen where I want it. These are some relevant, though incomplete, methods that should move an object already painted on screen:
Console class
Java Code:
public void doMoveCommand(String cmd, String arg, String xpos, String ypos) { int x = Integer.parseInt(xpos); int y = Integer.parseInt(ypos); if (cmd.equals("posMake") && arg.equals("star")) { box.moveStar(box.historyG.get(1), x, y); //historyG is an arraylist of GPolygons freeCommand();
[Code] ....
When I say makepos(whatever) I am getting a arraylist out of bounds exception. How I might be able to accomplish moving objects already on screen?
I have a project where I must sort a collection of songs by a number of fields: year, rank, title and artist. in the project, we must use certain methods and we cannot add others without getting marked down. Here are the specific requirements:
Sorting
The -sortBy option will cause the output to be sorted by a particular field. If this option is specified, the output should be ordered according to the field named. If there are ties, the tied songs should appear in same order in which they were in the input file. If no -sortBy option is specified, the output should maintain the order of the input file.
public void sortYear()
Order the songs in this collection by year (ascending).public void sortRank() Order the songs in this collection by rank (ascending).public void sortArtist() Order the songs in this collection lexicographically by artist (ascending, case-insensitive).public void sortTitle() Order the songs in this collection lexicographically by title (ascending, case-insensitive).
I've tried a couple ways to do it, and they don't work. I'm aiming for functionality like I got with the regular for loop, but from an enhanced for loop. Is this simply beyond the scope of an enhanced for loop, or am I just not getting the right syntax?
TestObject to1 = new TestObject("first", 11); TestObject to2 = new TestObject("second", 12); TestObject to3 = new TestObject("third", 13); TestObject to4 = new TestObject("fourth", 14); TestObject to5 = new TestObject(); List<TestObject> testList; testList = new ArrayList<TestObject>();
[code]....
The TestObject class is simply an int and a String, with getters getInt and getString. It all works fine with the regular for loop.
edit: I should probably mention that I know what I have in the enhanced for loop now will only display the class name and the hash. I've tried adding the .getString and .getInt, and tried a few other ways to make it work. I just reverted to this because it compiles and runs
I have an Array of objects that contains strings. I am new to Java and have read books, the Java docs, and searched the Internet for my problem to no avail. How can I get my strings to print in a list so that the user can select an object to manipulate its attributes? I have a class called Instruments and created 10 guitar objects. Here is the code:
Instrument [] guitar = new Instrument[10]; for (int i = 0; i < 10; i++) { guitar[0] = new Instrument("Guitar 1"); guitar[1] = new Instrument("Guitar 2"); guitar[2] = new Instrument("Guitar 3"); guitar[3] = new Instrument("Guitar 4");
Basically the class is supposed to have a static variable that keeps track of the number of companies (numberOfCompanies) that have been created and a static method that returns the value of this variable. I need to have a constructor and a method to addEmployee, a method to printCompany, and a toString method. The addEmployee method will check that there is only 1 salesperson, 2 designers, and 4 manufacturing persons at a time and will check that there are no more than 7 employees of the company.
The addEmployee method will return a String indicating what the error is (i.e. "There is already a sales person in this company") or a null if the employee was added. If attempting to name a third company, an error message will be shown. what i have so far but my print company mmethod returns null company class :in which i am obliged to use inputdialog because it says that it cannot return void when i use the showmeassage diaolog.
company class:
import java.util.ArrayList; import javax.swing.JOptionPane; public class Company { private ArrayList<Employees> list ; private static int numberOfCompanies;
[Code] ....
error message when print button is clicked:
Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: JOptionPane: parentComponent does not have a valid parent at javax.swing.JOptionPane.createInternalFrame(Unknown Source) at javax.swing.JOptionPane.showInternalOptionDialog(Unknown Source) at javax.swing.JOptionPane.showInternalMessageDialog(Unknown Source)
