Java

Java - Calculation in NEW array

11-Aug-15 6:20

This is another non-question. Please follow the link I gave you below and read it carefully.

Re: how to build 3d box

Neo1010115-Aug-15 2:46

Neo10101

15-Aug-15 2:46

It looks like I'm not the only one you show this autistic behavior towards. Bye.

Frankie124511-Aug-15 5:36

Re: Java - Calculation in NEW array

11-Aug-15 5:36

Hey All,

Working on a project to create an array holding double type data then squaring each element into a new array. Can someone help explain how to store the calculations into a new array? Thanks!

public class Problem_3{
    public static void main(String[] args){
        double[] myList = {1.2,4.7,3.9,4.0};

        //Print all the array elemts
        for (int i = 0; i < myList.length; i++){
            System.out.println(myList[i]+" ");}

            //Square all elements of the array into a new array
            
            for (int i=0; i<myList.length; i++){
              double[] square = myList[i]* myList[i];}

        

        }
    }

Richard MacCutchan11-Aug-15 6:15

11-Aug-15 6:15

Java

double[] square = myList[i]* myList[i];

... does not mean anything. you are trying to declare an array but without creating anything more than a number. Did you go through the tutorials I gave you the links for? They expalin how to create arrays, store and update the content, copy them to new arrays etc.

BTW what you need is:

Java

// create a new array of the correct size
double[] square = new double[myList.length];

// for each element in the original array
for (int i=0; i<myList.length; i++){
    // calculate the square of the value, and store
    // it in the appropriate cell of the array of squares.
    square[i] = myList[i] * myList[i]; // store th
}

Delimiters

Member 107286679-Aug-15 10:58

Member 10728667

9-Aug-15 10:58

How do I separate my input with a tokenizer and delimiter?

Java

import java.io.BufferedWriter;
import java.io.FileWriter;

import javax.swing.JFrame;
import javax.swing.JPanel;

/*******************************************************************************************
Program Name: ClientInformation.java
Programmer's Name: Elizabeth Conklin
Program Description: This program will accept user input and save the input to a file.
*******************************************************************************************/
public class WClientTest {

    public static void main(String[] args) {

        WClient myWClient = new WClient();
        myWClient.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myWClient.setSize(650, 175);
        myWClient.setTitle("Client Information");
        myWClient.setVisible(true); 
    }
}

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

import java.io.*;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class WClient extends JFrame {

    JLabel labelName;
    JLabel labelID;
    JLabel labelStartingBalance;
    JLabel labelClosingBalance;
    JTextField textName;
    JTextField textID;
    JTextField textStartingBalance;
    JTextField textClosingBalance;
    JButton buttonSave;

    public WClient() {
        setLayout(new GridLayout(0,4));

        labelName = new JLabel("Client Name: ");
        add(labelName);
        textName = new JTextField(10);
        add(textName);
        labelID = new JLabel("Client ID: ");
        add(labelID);
        textID = new JTextField(10);
        add(textID);
        labelStartingBalance = new JLabel("Starting Balance: ");
        add(labelStartingBalance);
        textStartingBalance = new JTextField(10);
        add(textStartingBalance);
        labelClosingBalance = new JLabel("Closing Balance: ");
        add(labelClosingBalance);
        textClosingBalance = new JTextField(10);
        add(textClosingBalance);
        buttonSave = new JButton("SAVE");
        add(buttonSave);

        event e = new event();
        buttonSave.addActionListener(e);}

    public class event implements ActionListener{
        public void actionPerformed(ActionEvent e) {
                try {
                    String name = textName.getText();
                    String ID = textID.getText();
                    String startingBalance = textStartingBalance.getText();
                    String closingBalance = textClosingBalance.getText();

                    textName.setText("");
                    textID.setText("");
                    textStartingBalance.setText("");
                    textClosingBalance.setText("");

                    BufferedWriter outfile = new BufferedWriter(new FileWriter("client.txt", true));

                    outfile.write(name);
                    outfile.write(ID);
                    outfile.write(startingBalance);
                    outfile.write(closingBalance);
                    outfile.close();}
                catch (Exception ex) {
                }
            }
        }{;
    }
}

modified 9-Aug-15 22:32pm.

Re: Delimiters

Richard MacCutchan10-Aug-15 0:56

10-Aug-15 0:56

Just write your own control character after each data item. You could use commas which will give you a CSV file that you can check by loading into Excel, or using a library method that understands .csv format.

Java Bubble Sort

Frankie12457-Aug-15 5:00

7-Aug-15 5:00

I recently did a project that asked the user to input a certain number of elements and then sort those in descending order.

I want to change it where there is no user input if the knowledge of the array is already been established for 10 integers in random order. Then sort them in descending order. 9876...etc

import java.util.Scanner;

class BubbbleHW {
  public static void main(String []args) {
    int num,
    int i,
    int j,
    int temp;
/*This will no longer be needed    
Scanner input = new Scanner(System.in);


  System.out.println(&quot;Enter the number of elements to sort:&quot;);
    num = input.nextInt();
This will no longer be needed*/

    int array[] = new int[num];
//Do I change  int array[] = new int [9]

//    System.out.println(&amp;quot;Enter &amp;quot; + //num + &amp;quot; elem,ents: &amp;quot;);

    for (i = 0; i &amp;lt; num; i++)
      array[i] = input.nextInt();

    for (i = 0; i &amp;lt; ( num - 1 ); i++) {
      for (j = 0; j &amp;lt; num - i - 1; j++) {
        if (array[j] &amp;lt; array[j+1])
        {
          temp = array[j];
          array[j] = array[j+1];
          array[j+1] = temp;
        }
      }
    }

    System.out.println(&amp;quot;Decended order of elemtns&amp;quot;);

    for (i = 0; i &amp;lt; num; i++)
      System.out.println(array[i]);
  }
}&lt;/pre&gt;</pre>

Richard MacCutchan7-Aug-15 6:21

7-Aug-15 6:21

And what is the question?

Frankie12457-Aug-15 6:37

7-Aug-15 6:37

Before the array was populated by
num = input.nextInt();

//so if the user entered 7 then the variable num before would become 7
int array[] = new int[num];

//Do I just need to change the array to this
int array[] = new int[9];

What do I need to change to that the array isn't being populated by the user input anymore but by an array that consists of 10 already known integers (0-9). I do not want to type out each integer such as int array[] = new int[0,1,3....]

Richard MacCutchan7-Aug-15 21:09

7-Aug-15 21:09

Yes, you just instantiate an array of the length you want, and use the Java Random[^] class to generate the values. Something like:

Java

int[] array = new int[9];
for (int i = 0; i < 9; ++i)
{
    array[i] = // next random generated integer
}

Frankie12459-Aug-15 9:33

9-Aug-15 9:33

Thnks for the help,

I'm still having issue with the output if anyone could continue to help with this problem. I want the program to generate 10 random integers and then sort them in descending order.

import java.util.Scanner;

class BubbbleHW {
  public static void main(String []args) {
    int i, j, temp;
    int array[] = new int[9];

    for (i = 0; i < array.length; i++)
      array[i] = (int) Math.random()*9;

    for (i = 0; i < ( array.length - 1 ); i++) {
      for (j = 0; j < array.length - i - 1; j++) {
        if (array[j] < array[j+1])
        {
          temp = array[j];
          array[j] = array[j+1];
          array[j+1] = temp;
        }
    }
    System.out.println(array);
}
    }

}

Richard MacCutchan10-Aug-15 0:54

10-Aug-15 0:54

A couple of obvious errors first:

Java

array[i] = (int) Math.random()*9;

You are casting the result of Math.random to an integer and multiplying the result by 9. But the return value of Math.random is a double greater than 0.0 and less than 1.0, so the integer result will always be zero. You need to do the multiplication first, thus:

Java

array[i] = (int)(Math.random() * 9);

Java

System.out.println(array);

This statement makes no sense, a primitive type or array has no toString method so you cannot use a statement like this to print its contents, you need to traverse the array and print each value, like:

Java

for (i = 0; i < array.length - 1; i++) {
    System.out.println(array[i]);
}

Now you should be able to see that your sort algorithm will not work. You need to check if the first element is greater than the second before swapping them. You also need a flag to check when no more values are out of order. I would use a while, or do/while loop with a boolean flag that can be set at the beginning, and reset every time an out of order pair is found. Try writing it down in your native language first so you understand the logic, and then write the actual code.

Frankie124510-Aug-15 3:22

10-Aug-15 3:22

Thank you! I looked over the errors and was able to resolve the problems you described. Sure these errors seem basic but I am trying to teach myself at the moment.

Thanks again!

Richard MacCutchan10-Aug-15 3:34

cennect unicenta with a phone problem

10-Aug-15 3:34

Frankie1245 wrote:
I am trying to teach myself at the moment.

Yes, I appreciate that, and we can see that you are making an effort. You may like to look at http://download.oracle.com/javase/tutorial/index.html[^] for some good learning materials, the basics and some of the specialised classes are covered in good clear detail.

Member 116403425-Aug-15 4:56

Member 11640342

5-Aug-15 4:56

good afternon,
plz i need a help to connect unicenta with a phone/smartphone
there is someone can help me plz
thank you Smile | :)

i'm using unicenta with netbeans so i'm coding this application with java

modified 5-Aug-15 11:56am.

Re: cennect unicenta with a phone

Richard MacCutchan5-Aug-15 5:23

See http://www.codeproject.com/Messages/3137511/Forum-Guidelines-PLEASE-READ.aspx[^].

5-Aug-15 5:23

Java Application Help - Inner Class?

Member 1072866731-Jul-15 21:43

Member 10728667

31-Jul-15 21:43

My program this week is to create an application that will calculate services (oil change, car wash, or both) provided to customers. The services should be totaled and a message box should display the services rendered and the total sales amount for the purchase. Also, the client should be able to clear the application for a new user. For whatever reason, this inner class is confusing me, and I'm not sure that I'm even on the right track. Any help would be greatly appreciated.

Java

import javax.swing.JFrame;

public class CarCareTest {

    public static void main(String[] args) {

        CarCare myCarCare = new CarCare();
        myCarCare.setSize(500, 500);
        myCarCare.setVisible(true);
        myCarCare.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

}

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JMenuBar;
import javax.swing.JOptionPane;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;

public class CarCare extends JFrame {

    //Declare Class Variables
    private JMenuItem bronzeOil, silverOil, goldOil;
    private JMenuItem basicWash, betterWash, bestWash;
    private JMenuItem total, clear, exit;
    private int priceOilChange, priceCarWash;

    //Create Constructor
    public CarCare(){
        super("Quick Fast Car Care");

        //Instantiate Top Level Menu Items
        JMenu oilchangeMenu = new JMenu ("Oil Change");
        JMenu carwashMenu = new JMenu ("Car Wash");
        JMenu totalclearexitMenu = new  JMenu ("Total/Clear/Exit");

        //Instantiate Sub Menu Items
        bronzeOil = new JMenuItem("Bronze");
        silverOil = new JMenuItem("Silver");
        goldOil = new JMenuItem("Gold");
        basicWash = new JMenuItem("Basic");
        betterWash = new JMenuItem("Better");
        bestWash = new JMenuItem("Best");
        total = new JMenuItem("Total");
        clear = new JMenuItem("Clear");
        exit = new JMenuItem("Exit");

        //Set Layout Manager
        setLayout(new FlowLayout());

        //Add Sub Menu Items To Top Level Menu
        oilchangeMenu.add(bronzeOil);
        oilchangeMenu.add(silverOil);
        oilchangeMenu.add(goldOil);
        carwashMenu.add(basicWash);
        carwashMenu.add(betterWash);
        carwashMenu.add(bestWash);
        totalclearexitMenu.add(total);
        totalclearexitMenu.add(clear);
        totalclearexitMenu.add(exit);

        //Create Menu Bar
        JMenuBar bar = new JMenuBar();

        //Add Top Level(s) To Menu Bar
        bar.add(oilchangeMenu);
        bar.add(carwashMenu);
        bar.add(totalclearexitMenu);

        //Add Menu Bar To JFrame 
        setJMenuBar(bar);

        //Create MenuHandlerObject
        MenuHandler handler = new MenuHandler();

        //Add Event Handling Listeners
        bronzeOil.addActionListener(handler);
        silverOil.addActionListener(handler);
        goldOil.addActionListener(handler);
        basicWash.addActionListener(handler);
        betterWash.addActionListener(handler);
        bestWash.addActionListener(handler);
        total.addActionListener(handler);
        clear.addActionListener(handler);
        exit.addActionListener(handler);
    }//End Constructor

        //Display Output

    //Create Inner Class
    private class MenuHandler implements ActionListener{
        public void actionPerformed(ActionEvent event) {
            System.out.println("MenuHandler Called.");

            //Determine Oil Change & Set Price 
            if (event.getSource() == bronzeOil){
                priceOilChange = 20;}
            else if (event.getSource() == silverOil);{
                priceOilChange = 25;}
            if (event.getSource() == goldOil){
                priceOilChange = 30;}

            //Determine Car Wash & Set Price
            if (event.getSource() == basicWash) {
                priceCarWash = 5;}
            else if (event.getSource() == betterWash);{
                priceCarWash = 10;}
            if (event.getSource() == bestWash){
                priceCarWash = 15;}

            //Determine Total
            if (event.getSource() == total){
            }

            //Clear Application
            if (event.getSource() == clear){
            }

            //Exit Application
            if (event.getSource() == exit){
            System.exit(0);}

        }//End ActionPerformed Method
    }//End MenuHandler Class
}//End CarCare Class

Re: Java Application Help - Inner Class?

Afzaal Ahmad Zeeshan2-Aug-15 1:55

Afzaal Ahmad Zeeshan

2-Aug-15 1:55

And what is your question?

It is pretty much unclear as to how to help you out in this context. Adding an inner class is fair and legal in Java. But, what is the question here? It is the logic that you want to be added or what?

The sh*t I complain about
It's like there ain't a cloud in the sky and it's raining out - Eminem
~! Firewall !~

JAVA SERVLETS and PHP

anaQata31-Jul-15 5:10

anaQata

31-Jul-15 5:10

I'm stuck between studying PHP and Java Servlets.

Is there any compelling reason to chose any over the other?

(I understand PHP is the most commonly used back end language)

I only have one semester to learn, and i can only chose one.

Any advice you would offer me given i have a java background. Confused | :confused:

Richard MacCutchan1-Aug-15 22:10

1-Aug-15 22:10

mainadmn wrote:
Is there any compelling reason to chose any over the other?

No.

mainadmn wrote:
Any advice you would offer me given i have a java background.

Choose the one that looks easiest to understand.

anaQata1-Aug-15 23:21

anaQata

1-Aug-15 23:21

so apart from that there's nothing to do with compatibility?
slow loading?
or anything else similar?

Richard MacCutchan2-Aug-15 1:12

2-Aug-15 1:12

Well, apart from the fact that you said you have only one semester to learn it, there was nothing in your question that would help make a decision. Whichever route you choose it is likely to be useful in giving you more experience of working with different systems. Only when you are applying for paid employment do the specific platforms and languages become important.