I am just starting to use ArrayLists for the first time. I was wondering if there is a way to automatically fill ArrayLists with a for loop.
For example:
ArrayList<Integer> numberList = new ArrayList<Integer>();
int limit;
Integer starter = new Integer(1);
[Code].....
I need to make an ArrayList with numbers 1-limit, inclusive, and rather than doing this with a regular array I am doing it with an ArrayList because I will need the remove() method later. Anyway, my question was if there is a way to fill an ArrayList with a for loop. My code doesn't work at the moment, giving this error: Array type expected; found: 'java.util.ArrayList<java.lang.Integer>'
I am having trouble conceptualizing how to fill arrays. I understand that I can declare one and number it's elements, and it stores values of a certain data types. I don't really understand beyond that. Like how I would fill and use data in it.
I can be more specific with an assignment I have for school, but need to get started understanding how to fill arrays with data and then how to use that data.
There is some kind of issue here.in the gui it will ask you to give points in time (ms) it wants to click for you, although when for example i put in 3 at "How Much Clicks" it asks 4 times and then exits with an error.Here is the error:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 3 at relax.Relax.StartSetup(Relax.java:175) at relax.Relax$2.actionPerformed(Relax.java:78) at javax.swing.AbstractButton.fireActionPerformed(Unk nown Source) at javax.swing.AbstractButton$Handler.actionPerformed (Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed (Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source)
I have created a method Rectangle and added a loop in my class Resizer (MouseAdapter) but impossible to resize the rectangles of the arraylist independantly !
class Rectangle extends Rectangle2D.Float{ private String name; public Rectangle(float x, float y, float width, float height, String name) { setRect(x, y, width, height); this.name = name;
I just started playing around with Java for awhile, but got caught up in a problem when using ArrayList.
CinemaAppMain public class CinemaAppMain { public static void main(String[] args) { new CinemaApp().start();
[Code]....
I am trying to get the movie name and theatre title from their ArrayList, and I know I need to go through the movie list & theatre list to find their name & title, and compare it with the user input and print out the result.
I use for(int i=0;i<movies.size();i++) to go through the the movie list, and I tried using for(int i=0;i<theatres.size();i++) to go through the theatre list. But when I printing multiple time with different user input value, it will show me strange result (screening have same movie name & theatre name, the else if statement is printed below the user input, user input is printed more than once after the first time).
Edit: I know its wrong for me to use nested for loop,if not, another solution is needed to get the item inside both of the list. (getting the "title" from movie list & "name" from theatre list)
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 a row of int JTextfields and i want to get a running total of the sum of all boxes in the last total JTextfield, as the user types.I understand its an actionlistener but whats the best way of doing it. What the action to listen out for?
So I an assignment in Java to write a code which will randomly populate squares in a Tic Tac Toe Board. I pretty much have it I think, but I cannot get the 'O' to appear on the board, some squares will be blank. We were told to use the Random utility to generate the squares. I am attaching the .gif's which are used. Here is my code:
import javax.swing.*; import java.awt.*; import java.util.Random; public class LandryTicTacToe extends JFrame { /** * */ private static final long serialVersionUID = -8781512780135301721L; private final int HEIGHT = 450;//Set value for Height private final int WIDTH = 500;//Set value for Width private static JButton [] button = new JButton[9];//Declare array of Buttons
Display a frame that contains nine labels, arranged like a Tic Tac Toe board. A label may display an image icon for X, an image icon for O, or nothing. Display images randomly in each label. Use the Random class to generate 0, 1, or 2, which corresponds to displaying an X image, an O image, or nothing.
I realized that I was not filling the array with anything but now I'm having issues filling it correctly. It's only filling the array with three of the user inputs ....
import java.util.Scanner; public class DriverSort { public static void main(String[] args) { Scanner scan =new Scanner(System.in); Sorter sorter = new Sorter(); int choice; // variable which says which sorting algorithm to use
I have run into a bit of a head scratcher, at least to me. I am building multiple rectangles using double precision. I had to switch from int to double due to another issue that requires decimal places. Now, my fillRect (last line in the code section I posted) is causing an error as it only wants to work with int.
public void draw(Graphics2D g2) { // check that sizes are above 0 if ((rectWidth <= 0) || (rectHeight <= 0))
I am trying to create an array filled with the object Card. It keep throwing the exception that the "deck is empty". I am not sure why that's happening because the code for filling the array seems fine.
public class Deck { private Card[] deck; private CardPile cardPile; private int numCards; public Deck() throws InvalidDataException{ this.deck = new Card[52];
I am passing input from the user to a method that will initialize an array of the data (scores in this case). The method is filling the entire array with the last input value.
array initializer method
Java Code:
public static float[] inputAllScores(float validScore) { float[] diverScores = new float[7]; for (int i = 0; i < diverScores.length; i++) { diverScores[i] = validScore; } return diverScores; } mh_sh_highlight_all('java');
I am trying to print a loop inside an array of a greater size than the loop itself. Like for example I have an array of size 7 but it has only 3 elements.
now what I want to do is print these three numbers in a loop so that my array[3]=2;array[4]=3;array[5]=4 ...... till the last one. Also the array could be any size and not just 7.
Here's the code: it's while loop inside a for loop to determine the proper length of a variable:
for (int i = 0; i < num; i++) { horse[i]=new thoroughbred(); boolean propernamelength = false; while (propernamelength==false){ String name = entry.getUserInput("Enter the name of horse "
[code]....
I was just wondering what was going on here -- I've initialized the variable, so why do I get this message? (actually the carat was under the variable name inside the parentheses.
I have everything else working. My problem is that when i type "quit" to close the outer loop. It still runs the inner loop. The National Bank manager wants you to code a program that reads each clients charges to their Credit Card account and outputs the average charge per client and the overall average for the total number of clients in the Bank.
Hint: The OUTER LOOP in your program should allow the user the name of the client and end the program when the name entered is QUIT.In addition to the outer loop, you need AN INNER LOOP that will allow the user to input the clients charge to his/her account by entering one charge at a time and end inputting the charges whenever she/he enters -1 for a value. This INNER LOOP will performed the Add for all the charges entered for a client and count the number of charges entered.
After INNER LOOP ends, the program calculates an average for this student. The average is calculated by dividing the Total into the number of charges entered. The program prints the average charge for that client, adds the Total to a GrandTotal, assigns zero to the Total and counter variables before it loops back to get the grade for another client.Use DecimalFormat or NumberFormat to format the numeric output to dollar amounts.
The output of the program should something like this:
John Smith average $850.00 Maria Gonzalez average $90.67 Terry Lucas average $959.00 Mickey Mouse course average $6,050.89 National Bank client average $1,987.67
Code:
public static void main(String[] args) { Scanner scan = new Scanner(System.in); String name = ""; int charge = 0; int count = -1; int total = 1; int grandtotal = 0; int average = 0;
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.
How to convert this program from a while loop to a for loop.
import java.util.Scanner; public class LongDivision { public static void main(String arguments[]){ Scanner input = new Scanner(System.in); System.out.println("Enter the dividend: ");
I am trying to make a program add values from a loop. So what its supposed to do is search through tokens on an imported file. The file lists State, Capital, and then capital population. Then take the population string, turn it into numbers, and then do stuff with the numbers. First I'm supposed to find the Highest and lowest population of the places in the file (which I did without problem), but the finally thing is I'm supposed to add each found population to the last so I can find the average of the populations.
I just cannot seem to grasp how to do that. I THINK I'm supposed to some how store the given value into a variable, but how do I get that variable to add to the new value?
like...? Get token -> a b = a c = a + b
or wait no.....
Java Code :
import java.io.*; import java.util.Scanner; public class CapPopS { public static void main(String[] args) throws IOException { File stateCAP = new File("state-capital-2004population.txt"); if (!stateCAP.exists())
I have an ArrayList of employee and ArrayLsit of bosses, and I want to keep those people in a temporary ArrayList , then ordain alphabetically by name, to sort I use the interface comparator.
The problem comes when I will order 2 ArrayList(workers and bosses), because every time I call I use these functions or not is ordered (sortByNameAlphabetical())
public class Employee { private String name; public String getName() { return name; } @Override public String toString() { return name ;
