Extending Calculator - Added Function To Square Numbers
Feb 14, 2014
I am new to java and during my classes we built a basic calculator. I want to extend my calculator and added function to square numbers.Here is my program:
I'm trying to create a cursor for a game that moves square by square. While it will move to the next square, though, it leaves the image of the previous cursor on the last square it was on.
As a visual explanation, this is what the program looks like on launch:
This is what it's suppose to look like after you press the right arrow key once (made by forcibly changing launch coordinates):
And this is what it actually looks like after you press the right arrow key once:
Here is the code for the program:
package cursortest; import javax.swing.*; import java.awt.*; import javax.imageio.*; import java.io.*; import java.awt.event.*; public class CursorTest extends JPanel implements KeyListener{
[Code] ......
I'm fully aware that I could just use g.clearRect on the area and remove it for sure, but I know for a fact I shouldn't have to as I have another program I made a long time ago that tried to do something similar without needing to resort to that.
So I was making a Java Calculator that only adds. The problem is that the numbers are not adding. I think it is because whatever has been clicked is not being saved to be added.
So I have a program for a project that permutes a random series of numbers using Java's Rand function. Basically I use a seed and a number of items I want in the arrangement of numbers, and the program makes a permutation with no two numbers being repeated. Only arrays can be applied to it, so I've been hard at work finding a solution.
Here's the code so far:
public static int permutation[]; public static void permute(int numOfItems, int seed){ permutation=new int[numItems]; Random rand = new Random(seed); permutation[0]=rand.nextInt(numItems-1);
[Code] ......
So basically I'm wanting the program to make a randomized list of numbers from the number of items I pass to the Permute method with no duplicates. I'm having some level of success with what I have written, as it gives me a randomized list when printing the output, but for some reason the first for statement in code never terminates fully, but instead runs indefinitely when generating the last integer.
For example, if I want to put 10 with a seed of 0 into it and make a list from 0-9, it will print 74283510, which is only 8 different integers. permutation[0] is manually set at the beginning of the method, which accounts for one more, but that's still only a list of 9, so I'm just wondering why the last integer is not being generated and why the program keeps looping and not terminating? I'm know for sure it's something I'm overlooking.
I want a simple jsp page that performs basic operations on numbers such as addition, subtraction, multiplication, division and modulus . How to run that file?
My verify method also always returns false. So I'm given three classes to begin with. Calculator, Expression, and InfixExpression and they are listed below.
The goal is to create a class called PostfixExpression that extends Expression and can read and calculate postfix expressions.
My evaluate() method works for most calculations but when it needs to return a negative value it just returns the positive equivalent.
Also, my verify method always returns false and I can't pinpoint why.
Here's my current code. Some things are commented out for debugging purposes.
import java.util.Scanner; /** * Simple calculator that reads infix expressions and evaluates them. */ public class Calculator { public static void main(String[] args) { Scanner input = new Scanner(System.in);
How can I make the numbers to stay at the textfield of my calculator instead of disappear like when I type 1 then hit the + sign the number 1 disappears from the textfield I would like to have this (1+1) showing in the text field and also if try to press only + , * , - , / to show error.
My teacher told me : It looks like everything is working except that in the Box, the method returns true if it is not a box.
The only other thing missing is the if statements in the main method using the .equals() method to do the comparisons. But, now I am lost on how to do my if statement.
HTML Code: private int height; /** * Constructor for objects of class box */ public Box3(int l, int w, int h) { // call superclass super(l, w); // initialise instance variables height = h;
I am writing a program that should take a url and scan the page for any links. It is in the beginning stages, but I ran into an error when I tried to extend a class. There's a lot going on in this code, but the error is caused by the constructor.
Error message at compile time:
"constructor Page in class Page cannot be applied to given types; {//Constructor ^ required: String found: no arguments reason: actual and formal argument lists differ in length".
Here's the code(first my class, then the class I extended)
public class SearchEngine extends Page { public static Color customGreen = new Color(69, 194, 33); public static Color customYellow = new Color(232, 166, 12); public static Color customBlue = new Color(25,97,255); public static Color customYellowComp = new Color(178,125,0);
Basically I want to make a class called library, but I don't want to make an interface because I actually want to define the methods. I think I can only use abstract classes but not really sure how to use those. But I still have a problem, I want to create a Map that classes implementing Library class have to have in their code, and the Map will be a HashMap with <String, ParentClassHere>, so basically let's say I make a class called Car, implemeing Library to the Car class would create a Map library = new HashMap<String, Car>. Can I do something like this? And also include methods to get values and set values to the library Map?
I want to remove the extends Canvas from the top line and when I use JFrame to add canvas, I don't do add.(this, but instead I do add a canvas variable I make. So instead of extending I want to make a variable. But then how would I do the start, stop and run?I want to use Graphics, Canvas (Not Jpanel because I want to use BufferedImage) & JFrame. I don't want to extend Canvas, how could I use Canvas identically to shown above but instead of extending using it as a variable? or, how could I do this?
I have a working program, except that it does not calculate the credit hours and the financial aid. When I enter an input, it works, until it should show the student name, credit hours and financial aid. the error i get from the command is "Hours invalid for false student". Here is the program i think i might have the problem.
import java.text.DecimalFormat; public abstract class Student { //initialise variables String name; int creditHrs;
I'm having a problem with SplitPane (horizontal Flow). What I'm looking for is to find a way to maintain the left pane in the same position when the main window maximizes. I do not want the left pane to grow on its width. If I go into the AnchorPain Constraint in the Scene Builder and remove the right and left constraints, when I run the application, the left pane keeps its position, but it appears a gap between the two panes (the left pane and the right one).
I need to find the way to expand the right pane to the position where the left pane is.
The link shows an image that illustrates the problem. [URL]
What is the difference between extending JFrame in one class and simply constructing a new JFrame object in that same class? What benefits do I have with each solution, providing I want to use that class to create the GUI. Is it the same or are there differences rather than not having to reference to a new JFrame to be able to use its functions?
1. Tried to use setLayout() but it wouldn't let me. Have imported libs
import javax.swing.*; import java.awt.*;
but it doesn't work. It only worked when I extended a class with JFrame. Why do I have to do it? I already have a JFrame instance:
public test(){ JFrame frame = new JFrame(); frame.setTitle("Workshop"); frame.setBounds(500,300,400,300); frame.setVisible(true); frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); .... }
This code runs smooth, so it's confusing for me that it lets me create a JFrame object, and put buttons onto it, but it wants me to extend the class onto JFrame class in order to use a method.
2. I've read somewhere that AWT is old and should not be used anymore. Is there a diagram or a list with objects and properties that are manipulated only by Swing so that I could concentrate only on those? For example (made up list):
I've been trying to pull data from another class file "Calculations.java" and have it be displayed in a TextField in "DataAnalyzerGUI.java". Here is how the hierarchy is broken down for my assignment:
I am creating a .jar for a game I made. I'm not using any dev tools, just a DOS console call to java: %~dp0....javajdkinjar.exe -cfmv TheSwarm.jar manifest.txt *
My manifext.txt contains:
Main-Class: Game
But when I compile the jar, its manifest contains:
And I get an error about it not finding the main class. Shouldn't my Main-Class setting be added to the jar? I can manually rename it to .zip and edit the Manifest.MF but that is a huge pain when I'm testing the .jar file and regenerating it often.
I have the following code. how can items be added to that list?
private List<IComponentNode> comp; interface IAAAView { // returns component with given code or null IComponentNode findComp(String a); // returns component with given renderer or null
I am trying to create a form where my customer can add some other fields(like: label,textbox), and he need to use that added fields for the next time he open the application...
I would like to know whether it is possible to save dynamically created controls and reuse it again...
I have a ace:dataTable which contains a variable number of columns. For this I use the c:forEach tag. All generated in the c:forEach are not displayed. In the sample, only columnLibelle and columnSum are displayed.
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core"
I'm just a java beginner. I've spent a lot of time installing and configuring software. I'm using Netbeans 7.3 on Windows 7, 64 bit. Recently, I downloaded opencsv from sourceforge.
With no previous experience adding libraries, I read a blog post on adding the library. I think that I then:
Start a new project.
Right click on libraries
Add jar/folder
Gave the temporary path to the .jar file
After, I read the blog post again, and realized I'd missed it. This time I did:
Right click library, Add library, Create library
However, I kept getting a message that the same library already existed. If I do the first process above, I will find the same library.
However, I see no way in Netbeans to remove it. I've deleted the test projects. And started a new one. But the library now exists for all projects it seems.
I've grepped all the files under the Netbean directory, searching for "opencsv", but found nothing. The only things in the Windows registry were locations of files.
How can I delete this library permanently from Netbeans? Short of, uninstall, then reinstall? Is there a way to list all the libraries that Netbeans has?
Here is my full program, you can find these lines of code on lines 64 and 70.
Java Code:
import java.util.Scanner; public class StockTransaction { public static void main(String[] args) { // TODO Auto-generated method stub //Variable Declaration Section
My panel named panelIncomeInfo are not showing the components that I have added.
public class PayrollGUI { private JPanel panelIncomeInfo = new JPanel (); private JPanel panel = new JPanel (); private JPanel panelPayCheckInfo = new JPanel (); private JButton close = new JButton ("Close");