I was learning looping in Java and decided to try this code and then I encountered an endless loop of 2s. why is that? I believe this line count=count++ caused it.
class ForDemo{
public static void main(String []args){
int count;
for(count=2;count<=5;count=count++)
System.out.println("count is:"+count);
System.out.println("Done!");
}
}
I'm making a program to demonstrate Exception Handling. (Note: the code was written inside towards out). The user is prompted to input two values (integers) and then the program will divide those values and output the result.
I then added the "try" and "catch keywords for exception handling-instead of the program shutting down if an error occurs, the words "you cant do that" will appear
I then added a while loop to allow the user another chance to input usable values. Of course, I made sure to make a termination to the loop as well.
Everything works as expected if the user inputs e.g 8 divided by 0. in that case exception occurse, the user is told "you cant do that", is then prompted to start over and so forth until he gives usable integers. then the program continues to the termination. However, if the user inputs a String , e.g 9 divided by xyz, then the program goes into an endless loop
My question is:
1) why does a String cause an endless loop ( I have a theory)
2)why does the loop occur as soon as I put in an incorrect value- is the while loop somehow in extant? somehow always waiting? (hard to picture it)
3) lastly, what would be the correct code to handle and exception caused by a String (as opposed to being caused by impossible to execute math)
Here is the program
package inschool;
/*
*GOAL: to allow for an exception to occur without causing the entire program to stop.
*NOTE: the coding was written from the center outwards (e.g first "System.out.println", then "try", then "do")
*/
import java.util.*;
public class L82_ExceptionHandling {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
[Code] .....
I've used Netbeans IDE to create a simple Swing JFrame container, class NewJFrame.
NewJFrame calls another JFrame with dialog in it. Problem is there is an endless call made to it. Here's the issue relevant piece of code:
//Code for calling class
package p;
public class NewJFrame extends javax.swing.JFrame implements ActionListener {
.........
public NewJFrame() {
initComponents(); //IDE auto generated code for binding
[Code] ....
I searched but i cannot understand why run class is getting called multiple times. I have attached the screen prints for both the screens. 2nd screen print(of called class) is very shallow since screen was blinking unstopped due to multiple calls, but i have attached a faint image of it.
I am having a problem with looping a while loop that contains a switch statement. Here is my code:
package hw4jenningsd;
import javax.swing.*;
public class HW4JenningsD {
[Code].....
looping through 2d arrays.
This code works when printing '*' to show the number of elements in a 2d array:
static int [][] gameboard = new int[3][7];
for (int i = 0; i < gameboard.length ; i++) {
for (int j = 0; j < gameboard[0].length ; j++) {
System.out.print("*");
Thread.sleep(1000);
but then this does not:
static int [][] gameboard = new int[3][7];
for (int i = 0; i < gameboard.length ; i++) {
for (int j = 0; j < gameboard[i].length ; j++) {
System.out.print("*");
Thread.sleep(1000);
The difference is on the third line where i did gameboard[i] instead of gameboard[0]. I get a runtime error on the second one.
Write a program that asks the user for the low and high integer in a range of integers. The program then asks the user for integers to be added up. The program computes two sums:
The sum of integers that are in the range (inclusive), and the sum of integers that are outside of the range. The user signals the end of input with a 0.
Your output should look like this:
Sample input/output
In-range Adder Low end of range: 20
High end of range: 50
Enter data: 21
Enter data: 60
Enter data: 49
Enter data: 30
Enter data: 91
Enter data: 0
Sum of in range values: 100
Sum of out of range values: 151
This is my assignment and below is my code.
import java.util.Scanner;
class InRangeAdder {
public static void main(String[] args) {
Scanner scan = new Scanner (System.in);
int low, high, data=1, rangesum=0, outrangesum=0;
[Code] ....
The problem is that the program simply gives an output of 0 for both "rangesum" and "outrangesum". I don't quite understand why that is. Also i have a quick question, the program needs me to end the program when the value of data is 0 but in order to initialize it I need to give it a value. Usually I would give it a value of 0 like I have for rangesum and outrangesum but if I do the program does not run till the loop as it considers the value of data to be 0 and ends the program right away. What would be a work around to this and when do I need to have a value to initialize an integer? for example, I do not need a value for low and high. Is this because the program recognizes that a value is going to be defined but cannot do that for the other integers as they are inside a loop?
I have a program ive been working on and it works, but the flags in the runnables seem to shift the output down 1. for instance i commented playa3. start(); to see whats going on, if i just run playa1 i got no issues, as soon as i enable playa2, i get this output:
Game continues...
Dealer places King and Queen on the table.
Game continues...
Dealer places Queen and Ace on the table.
Player one with 'Ace' places his card on the table.
Player one with 'Ace' wins the current deal.
King Queen
Game continues...
Dealer places Queen and King on the table.
Player two with 'King' places his card on the table.
Player two with 'King' wins the current deal.
Queen Ace
the second time the dealer deals, player one places his cards on the table when he was supposed to do that for the first deal which he didnt. the last line there, (king queen) is just a print statement that is referring to the dealers hand that, that iteration is responding too. below is my code, i
import java.util.*;
import java.io.*;
import java.lang.*;
public class P5
{
public static int i, count, dealerFirstCard, dealerSecondCard, player1, player2, player3;
public static String cardSet [] = {"Ace","King", "Queen"};
public static volatile boolean dealerFinished= false;
public static volatile boolean playersFinished= false;
[code]....
I'm having some issues, trying to solve this problem in java. I want to print some election results, and i have to loop through a vector of objects and retrieve the partial sums of each party's seats for each constituency and the national results for each party. For now i can print the results per contituency, but i'm having problems in getting the national results. Like, adding the seats for labour party in Constituency A and B and C, etc, and print the sum. And do the same for conservative party.
This is what i have.
Java Code:
while (i < h.geral.size()) {
show += "Constituency - "
+ ((Party) h.geral.elementAt(i)).getConstituency() + "
[Code] .....
int x = 10;
do{
System.out.print("value of x : " + x );
x++;
System.out.print("");
}while( x + x == 22 );
When i put x+x==22 than it gives 2 values of x which are 10 and 11, they are wrong but when i put any other value like x+x==24 it just shows 1 value which is 10. I am not able to understand what mistake is there. I have been searching it for past whole month but didn't got any reason.
The player is defined as having 8 attributes which are in the array. The user enter attribute ratings that are restricted between 1 and 10. The total number of attribute points per player to allocate is 60. So my checks are that the inputted numbers are between 1 and 10 and the sum of them is 60. I continue to get an infinite loop when the code hits the if statement defining jamesTotalQuarter != 60. The code works however if the total is 60. What I want it to do is if the total != 60 revert back to the top of the code to allow the user to re-input their ratings. I've tried different combinations of continue and break statements without the outcome I'm looking for.
[public static void lebronJames() {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
//Declare an array to hold 8 intgers values
int lebronJamesAttributes[] = new int[8];
int attribute = 0;
System.out.println("Please allocate your attribute points for Lebron James in the following order. Your point allocations per attribute should be between 1 and 10. You have a total of 60 points to allocate");
System.out.println("-----------------");
System.out.println("Close Range" + "
[code]....
I have written a small program that creates a loop that only fails to continue once we reach a StackOverflowError exception. It looks just like:
class MyFirstApp {
static int counter;
public static void main(String[] args) {
counter++;
System.out.println(counter + " in main.");
roundAbout();
}
public static void roundAbout() {
counter++;
System.out.println(counter + " in roundAbout.");
main( new String[0] );
}
}
The idea of the program is to go between each method without using an object. Each time the method is entered the static int counter variable is incremented and outputted along with its respective loop. The loop does, however, fail eventually.
By calling the between the methods we build a tower of stack frames that eventually topples. The number of times this runs before the StackOverflowError occurs varies, though. Sometimes I get 6553, 6554 or something else close to these values.
Is there a way to pop a method of the stack or clear part of the stack so I can keep this going? I don't know where I would use this but it would be nice to know.
Im working on an assignment with the following instructions:
Create a Date class with the following capabilities:
a)Output the date in multiple formats such as
MM/DD/YYYY
June 14, 1992
b )Use overloaded constructors to create Date objects initialized with dates of the formats in part a).
You should only have 3 member data: integer month, integer day, and integer year. Also, you should have at least 2 constructors and 2 methods in your Date.java.
how to have an application restart if the user inputs an incorrect integer in a JOptionPane question? I know how to do it with the Scanner class but nothing I do seems to work. This is the beginning of my code:
import javax.swing.JOptionPane;
public class Pay {
public static void main(String[] args) {
String level = JOptionPane.showInputDialog("Please select your skill level: 1, 2, or 3");
int levelPick = Integer.parseInt(level);
[code]...
I'm making a program to handle temperature conversion. All the math is working properly, but I'm having trouble with making a loop to not let the user proceed until a valid input is given. The expected input is a double, then a space (though I found using enter works as well), then a char to represent Fahrenheit or Celsius. If I run this piece of code in the entire program with proper input, it works. When I use an invalid input, the catch works, and the code loops, but then the user isn't allowed to enter a new input, so thirdTester stays as equal to 2, so the loop repeats indefinitely.
do{
try{
System.out.println("Enter the temperature (example: 98.35 F).");
temperature = keyboard.nextDouble();
unit = (keyboard.next().charAt(0));
[Code] ....
I have a piece of code for an applet that I want to run as the main applet code, and I want it to loop until a boolean is true, but it needs to paint while the code is looping. Here is the relevant part of my code ....
public void paint(Graphics g)
{
g.drawImage(background, 0, 0, this);
if(over == false)
{
tick();
[Code] ....
(I have tried replacing the if with a for, that does not work.)
I am working on my second javafx program and I am getting confused. The program that I am writing is a payroll calculator. A secondary window opens at the start of the program where the user first enters the number of employees and clicks submit to save the number and to close this window. Then, the user begins to enters the employee information (first name, last name, pay rate and hours worked) when the user clicks the NextEmp button, I want the data in the text fields to be entered into arrays for later use, then clear the fields for the next use. I am running into 2 issues. The first is the close event for the secondary window that pops up. I cannot figure out the syntax. The second issue that I am running into is the loop to store the data into the arrays. I believe I am getting the text field data correctly, but I cannot figure out how to stop the loop until the NextEmp button is pressed again.
import javafx.application.Application;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.scene.input.KeyCode;
[Code] .....
How to create a MAGIC SQUARE, i just wanted to learn the logic of it .. with 2d array and looping..
View Replies View RelatedI am trying to test values stored in 2d arrays once but i my program just keeps looping what am i doing wrong
Java Code:
tempi=i;
tempx=x;
for( i=0;i<3;i++) {
for( x=0;x<4;x++) {
if(rounded[i][x]<395 || rounded[i][x] >405) {
System.out.println("there is an error with probes "+rounded[i][x]);
[Code] .....
I am looping through data in Android, using Parse data. I came up with this as a way to get user information; the larger goal is to create a model of data that I can use in an array adapter, so I can create a custom list view (as described here [URL] .... In the example, the data are hard-coded, not pulled from a database.
public static ArrayList<Midwifefirm> getUsers() {
//Parse data to get users
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.orderByAscending(ParseConstants.KEY_PRACTICE_NAME);
query.findInBackground(new FindCallback<ParseUser>() {
[Code] ....
The intention is that for every user that does not have the type patient, collect this data about them, then store it in the arrayList.
On the return statement, though, there is an error: cannot return a value from a method with a void return type.
I may be over complicating this...read through various sources to get a model for this...in the end, I want to display a list of information about specific users, after the user makes a selection of a city...it would therefore display all the information about the medical practices in that city.
How can i do this in best way, i what to avoid infinite loop .....
The use case is i get value from use and query value from database,sometime use can send value which return null in database,i what to avoid those null value .....
Basically I have to enter 5 numbers that I put through a loop and they print the star * depending on the number.An example would be this 5:*****. However, my codes prints out 5:*; 5 times. How to correct my code
Java Code:
import java.util.Scanner;
public class IntegerOutput
{
public static void main( String args[] )
{
Scanner input = new Scanner( System.in );
int num1;
int num2;
int num3;
int num4;
int num5;
[code]....
So I have been busy at some projects lately. One of them having this projectill put up the full code and the part i have problems with:
package relax;
//importeverything
import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.ArrayList;
[code]....
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)
[code]....
how does this nested enhanced for loop execute? I dont know how to indent the code.
for (String exam : exams)
for (String level : levels)
for (String grade : grades)
System.out.println(exam+":"+level+":"+grade);
Note:
exams,levels,grades are arraylist
exams contain Java,Oracle
levels contain Basic,Advanced
grades contain pass,fail
Write a java program that uses a While loop and persistent output to count down from 33 to 0 by threes, and put each value on a separate line, also do this in for loop.
View Replies View RelatedIts a basic program that is played by 2 people. Player one is suppose to type a number and the second player is suppose to guess the number. However after I test it out, and if I guess too low or too high I get stuck in "Your guess is too low, try again." infinite loop, what is wrong.
import java.io.*;
class GuessingGame
{
public static void main (String[] args) throws IOException
{
BufferedReader stdin = new BufferedReader (new InputStreamReader (System.in));
String firstPlayer, secondPlayer;
int firstInput, secondInput;
int guessCount = 0;
[Code] .....
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)