I'm working on a program where the user inputs song information (name, artist, filesize, duration) which is stored in a database. Once the user adds a song, the details should be stored in the first empty song slot (4 song slots total) and then taken back to the menu interface.
What I'm having trouble with is that I can add the first song fine (song1), but when I try to add another song, the information entered into song1 is gone. I've worked out that this is because every time I call upon the addNewSong() method, I'm creating four Song objects that are brand new with the line:
Song song1 = new Song();
Song song2 = new Song();
Song song3 = new Song();
Song song4 = new Song();
How to fix this problem is where I'm stuck because if I move these lines elsewhere, I get a 'cannot find symbol - variable song1' error.
Here is my code:
public class SongDatabase {
Scanner console = new Scanner(System.in);
public void addNewSong() {
Song song1 = new Song();
Song song2 = new Song();
Song song3 = new Song();
Song song4 = new Song();
if (song1.isEmpty()) {
After this problem is fixed, my math game will run. The answer variable is supposed to be equal to the cases in the second switch statement by random but I get errors whenever I try to initialize it this way. I have been writing this program for almost 5 days now and it is finally wrapping up. Why I can't map the answer variable to the second switch statement the way I want to?
package pkgnew; import java.util.Scanner; import java.util.Random; public class New { public static void main(String args[]) { //Declare and construct variables Random randomnum = new Random(); int fnum, snum, answer;
What's up with this. Just trying to test my hands on java packages, and had this error(by java) after successful compilation:
Error occurred during initialization of VM java.lang.Error: Properties init: Could not determine current working directory. at java.lang.System.initProperties(Native Method) at java.lang.System.initializeSystemClass(System.java :1119)
Main.java
package com.aceix.simplecalc; import com.aceix.simplecalc.inputhandler.InputHandler; import com.aceix.simplecalc.mathoperation.MathOperation; public class Main { public static void main(String[] args) {
Write a program to input a person''s age and salary, if the age is over 32, add $100 if otherwise subtract $500 from salary, finally output the age and new salary here is my code. I am getting a red line underneath the word 'salary' and i would like to know why and why i have to initialize it. and this is what i have tried.
</Scanner scan = new Scanner (System.in);/> </int age, sum, difference, old_salary, new_salary, salary;/> </System.out.println("Please enter the person age");/> </age = scan.nextInt();/>
initialize the min and max to be the first numbers entered, need to improve the code, because if the number entered is < 0 there is an error. but i dont understand how i would initialize to the first number entered, my understanding is tha if the user enters a 5 , then i should initialize to value 5, but i cant anticipate what the user will enter. I could initializa to null, but that still is not the first number entered.
int min = 0; int max = 0; int option = JOptionPane.YES_OPTION; while ( option == JOptionPane.YES_OPTION){
The problem is to figure out the number of cartons needed to box up the strawberries picked by the farmer and his wife. The farmer picks 8.4 lbs per hour and the wife pick 10.8 pounds per hour. They pick from 8 am until 4Pm (8 hours). You can put 20 pounds per box.I understand the word problem and how to declare and initialize variables. I'm just confused how to display the math into java to solve it.
I'm trying to make an array of objects, which I then initialize using objects that I have already created. I have main class, a secondary "Other" class, and a third "Other2" class. In the first Other class, I create three objects of the Other2 class, an object array of the type Other2 , and I then try to add the three objects to the object array, which results in the errors:cannot find symbol: class objectArray, ] expected, identifier expected
here is my code:
Other class public class Other { Other2 object1 = new Other2(); Other2 object2 = new Other2(); Other2 object3 = new Other2();
Write a program OutCircle.java that declares and initializes three floating-point variables (r, x, y): the first variable represents the radius r of a circle centered at (0,0) and the second and third variables are the coordinates (x, y) of a point in the plane.Your program should print true if the point is outside the circle and false otherwise. Hint: A point is outside the circle when its distance to the center is greater than the radius.
I am trying to use a custom listener to initialize database connection pool (C3P0) on start up and then destroy on context shut down. The reason for that is that I whenever context is shutdown I have a memory leak because initialized connection pool is not being destroyed.
I have a static class called C3P0Utils that deals with connection pool. In my listener in contextInitialized method I have tried at first to init the pool like this :
I know that object is created. I checked it using jconsole. However it is not accessible with in the application. My second attempt was to regester the pool and then add it to the context and then when I need it read from there.
The term "Local variable" is related to scope. That is a local variable is one which is defined in a certain block of code, and its scope is confined inside that block of code.And a "Member variable" is simple an instance variable.
I read in a discussion forum that when local variables are declared (example code below), their name reservation takes place in memory but they are not automatically initialized to anything. On the other hand, when member variables are declared, they are automatically initialized to null by default.
Java Code: public void myFunction () { int [] myInt; // A local, member variable (because "static" keyword is not there) declared } mh_sh_highlight_all('java');
So it seems that they are comparing local variables and member variables. While I think a member variable can also be be local in a block of code, isn't it?
when we create another variable and set it equal to the first : Car c2 = c1;
we're pointing c2 at the same car object that c1 points to (as opposed to pointing c2 at c1, which in turn points at the car). So if we have code like,
Car c1 = new Car(); Car[] cA = {c1, c1, c1, c1};
are we doing the same? Are we creating four *new* reference variables, each of which points at the same car (again as opposed to pointing them at c1 itself)? I think so, but want to make sure I'm understanding this correctly.
I have a JFrame jf and JPanel jp on it. jp has five TextFields named cel1, cel2.. cel5. I wish to construct a String Cel + for loop index and run a for loop to reset the values of all the text fields using a single statement such as cel1.SetText("abc"). Similar things can be done in foxfro. How does one do it in java?
How do I use a variable in an if statement to return a public void method from another class? I've tried:
System.out.print("select 1 - 6: "); Scanner myScanner = new Scanner(System.in); myScanner.nextInt(); if (myScanner.nextInt()==1) { carSelection colour = new carSelection(); colour.carSelection();
The method colour in class car selection is just 4 print line statements? I've // out the if statement to see if it is correctly calling the method and displaying the data and it is?
Regarding the code examples in Head First Java, this is from Chapter 5, regarding the beginning creation of the dot com game. There are two classes in quesiton
the first is the SimpleDotComTester class: public class SimpleDotComTester { public static void main(String[] args) { SimpleDotCom dot = new SimpleDotCom(); int[] locations = {2, 3, 4}; dot.setLocationCells(locations); String userGuess = "2"; String result = dot.checkYourself(userGuess); } }
and the second one is the code for the checkYourself () method in the SimpleDotCom class
public class SimpleDotCom { int[] locationCells; int numOfHits = 0;
public void setLocationCells(int[] locs)
[code]....
Now I noticed that both classes use a variable called result; the program runs fine, but assume from the example that you can use the same variable name two different classes;
i have a datatable with id= tblId#{emp.id} <c:set var="tableID" value="tblId#{emp.id}"> displaying employee details inside c:forEach closing dataTable.
[code]...
For ex.Displaying 5 table dynamically.Need to validate check box selected or not.5 table are displayed.But it shows 5th table row id only.It is because of local varible declaration?
I'm making a program where the user enters an ID number and can submit the amount of sales that person made for a specific product and write to a file. One of the things I have to do is making a running sum of the sales for each product for all people combined as well as an accumulation of the a persons sales every time he enters data. Everything seems to be working execpt my values like person1Total, person2Total...etx and product2Total.
When I try to write them to the file, they always come out at 0.0 even though they should be the sum of the indexes of the array sales.
I trying to display the value of a variable from a method, but I don't know why it will I can't do it.
//Java extension package import javax.swing.JOptionPane; public class Palindrome { public static void main(String[] args) { int number = 0; int palindrome = 0;
I have code that displays 3 game scores the series total and average. For some reason game 3 outputs 0 and game 1 and 2 output correctly. I don't see anything different that game 3 is doing that game 1 and game 2 aren't so I'm not sure what the problem is.
java file
package com.valenciaprogrammers.mybowlingscores; import java.text.DateFormat; import java.util.ArrayList; import java.util.Collections; import java.util.Date; public class BowlingScores implements Comparable<BowlingScores>{ private long id;
