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A couple of obvious errors first:
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:
array[i] = (int)(Math.random() * 9);
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:
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.
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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!
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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.
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good afternon,
plz i need a help to connect unicenta with a phone/smartphone
there is someone can help me plz
thank you
i'm using unicenta with netbeans so i'm coding this application with java
modified 5-Aug-15 11:56am.
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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.
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 {
private JMenuItem bronzeOil, silverOil, goldOil;
private JMenuItem basicWash, betterWash, bestWash;
private JMenuItem total, clear, exit;
private int priceOilChange, priceCarWash;
public CarCare(){
super("Quick Fast Car Care");
JMenu oilchangeMenu = new JMenu ("Oil Change");
JMenu carwashMenu = new JMenu ("Car Wash");
JMenu totalclearexitMenu = new JMenu ("Total/Clear/Exit");
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");
setLayout(new FlowLayout());
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);
JMenuBar bar = new JMenuBar();
bar.add(oilchangeMenu);
bar.add(carwashMenu);
bar.add(totalclearexitMenu);
setJMenuBar(bar);
MenuHandler handler = new MenuHandler();
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);
}
private class MenuHandler implements ActionListener{
public void actionPerformed(ActionEvent event) {
System.out.println("MenuHandler Called.");
if (event.getSource() == bronzeOil){
priceOilChange = 20;}
else if (event.getSource() == silverOil);{
priceOilChange = 25;}
if (event.getSource() == goldOil){
priceOilChange = 30;}
if (event.getSource() == basicWash) {
priceCarWash = 5;}
else if (event.getSource() == betterWash);{
priceCarWash = 10;}
if (event.getSource() == bestWash){
priceCarWash = 15;}
if (event.getSource() == total){
}
if (event.getSource() == clear){
}
if (event.getSource() == exit){
System.exit(0);}
}
}
}
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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 !~
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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.
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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.
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so apart from that there's nothing to do with compatibility?
slow loading?
or anything else similar?
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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.
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if u have a java background no need of learning php..and php is not a back end lang
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I would like to track client mac address when he/she is browsing my website.
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Do you mean by JavaScript? That's not Java.
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Hi, I'm doing my school project called 81 cards puzzle game using java. But I have no idea how to do. Can anyone have any reference source code for some kinda project like that? I don't know how to write to represent that 81 cards in java class? Please someone help quickly.
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I am having trouble in only the last line of code. (I think!) The first label prompts the user for their name. If they click the button, then it will change the second label to read "Hello, (username)!" Can anyone give me some pointers?
import java.applet.Applet;
import java.awt.Button;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class Greeting extends Applet implements ActionListener {
JLabel labelName = new JLabel("Please enter your name.");
JTextField textField = new JTextField(20);
Button button = new Button("GREET");
JLabel labelResult = new JLabel("Result goes here.");
String userResult = "";
public void init() {
setSize(500, 500);
setBackground(Color.yellow);
add(labelName);
add(textField);
add(button);
add(labelResult);
button.addActionListener(this);
}
public String getText() {
return userResult;
}
public void setName(String result){
userResult = result;
}
public void actionPerformed(ActionEvent event) {
if (event.getSource() == button) {
labelResult.setText("Hello, " + userResult);
}
}
}
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You have not included any code to get the user's name from textField . And your getter and setter are mismatched. You need something like:
public String getName() {
return userResult;
}
public void setName(String result){
userResult = result;
}
public void actionPerformed(ActionEvent event) {
if (event.getSource() == button) {
setName(textField.toString());
labelResult.setText("Hello, " + getName());
}
}
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someone told me applets are dead?
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Someone told me that Leslie was alive.
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I cannot figure out what I am doing wrong. I just don't feel like I'm ever going to understand all of this. My prompts and loop are working fine. However, I am not getting any output. I'm sure it's a fairly simple thing, but I just don't see it so I can't know for sure what I need to fix. I have watched all the videos and looked through my textbook and the internet, but I need someone to "dumb" it down for me, I guess. Thank you, in advance, for your patience and help.
import java.util.Scanner;
public class StudentInfoTest
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
String answer = "";
double GPA = 0.0;
StudentInfo info = new StudentInfo(null, 0, 0);
System.out.print("Enter student name: ");
String name = input.nextLine();
info.setName(name);
do
{
System.out.print("Enter class credits: ");
String credits = input.nextLine();
System.out.print("Enter letter grade: ");
String grade = input.nextLine();
System.out.print("Add another class? (Y or N): ");
answer = input.nextLine();
}
while (answer.equals("Y"));
System.out.printf(name + ", Your GPA is %.2f/n.", GPA);
}
}
public class StudentInfo {
private String studentName;
private double totalPoints;
private double totalCredits;
public StudentInfo(String name, double points, double credits)
{
studentName = name;
totalPoints = points;
totalCredits = credits;
}
public void setName(String name)
{
studentName = name;
}
public String getName()
{
return studentName;
}
public void addClass(double credits, String grade)
{
double points = 0.0;
if(grade == "A" | grade == "a")
points = 4.0;
if(grade == "B" | grade == "b")
points = 3.0;
if(grade == "C" | grade == "c")
points = 2.0;
if(grade == "D" | grade == "d")
points = 1.0;
if(grade == "F" | grade == "f")
points = 0.0;
totalCredits += credits;
totalPoints += (points * credits);
}
public double getGPA(double totalPoints, double totalCredits)
{
double GPA = 0.0;
GPA = totalPoints / totalCredits;
return GPA;
}
public static void displayStudent(String name, double GPA)
{
}
}
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If I understand your question correctly, you never get the correct GPA? If that is the case, it looks like you never call getGPA , you only use the initial (0.0) value.
So instead of
System.out.printf(name + ", Your GPA is %.2f/n.", GPA);
Should you have
System.out.printf(name + ", Your GPA is %.2f/n.", info.getGPA());
The same applies to credits and grade. You never seem to call addClass
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I guess I don't understand what I am supposed to do to call them...
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Have a look at the example I wrote. The same way, after you have got the input from the user call the addClass method with your variables...
Something like
info.addClass(credits, grade);
Just keep in mind that the next thing you should implement is proper conversion between the data types (from string to double)
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