I just went through some multiple choice questions and found this question with the below choices,
a) It is not standardized
b) To avoid conflicts since assemblers and loaders use such names
c) To avoid conflicts since library routines use such names
d) To avoid conflicts with environment variables of an operating system
Now , what should be the explanation for answering such question.
What is the starting index for linked list, 0 or 1. I know an array starts at 0 so wouldn't a linked list?
View Replies View RelatedI want to find a certain element in array I have to scan through the array index starting from 0 until I find the number I am looking for. Even in data structures which use hashing like HashMap and Hashtable we will have to scan through the keys until we find the key we are looking for. So what is the use of hashing over index based searching? I mean how is hashing an advantage over an array?
View Replies View RelatedI'm trying to create a Label using AWT (not swing) that is invisible on startup but shows up when pressung a button. Here's the relevant code:
Label:
updated = makeConfirmedLabel("Updated!");
updated.setVisible(false);
Button:
update = new Button("Update");
update.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent evt) {
MainComponent.updateComponents();
System.out.println(updated.isVisible());
updated.setVisible(true);
System.out.println(updated.isVisible());
}
});
When I press the button I get the following output in console:
false
true
If I start with setVisible(true) and use updated.setVisible(!updated.isVisible()) it works fine. Why can't I start with it hidden??
I tried to use updated.revalidate() after setting it visible. That made it work but it makes the whole UI flicker when pushing the button which isnt desired.
Now I am doing dictionary app using files..
Here i want to print the String from Starting character which is given by user..Here i given below the image like my concept..here we put .(dot and enter R)eclipse will print the method name which is starting from R..
I need to modify the drawShape method to calculate the distance from the starting point (the diameter) of any shape regardless of how many sides I give it, but I have absolutely no clue where to begin with this. The ultimate goal of the program is to calculate the value of pi using the shape that is drawn.
Here is the code:
public class PiTurtle extends Turtle
{
private double mySize;
private int mySides;
private double diameter = 0;
final static double startX = 590.0;
final double startY;
public PiTurtle(int nSides)
[Code] .....
This screen appears for a second and after this, it shows up normal app screen. How I can solve this issue? When I open app: after this
View Replies View RelatedI want to read a text file from the starting point to end of the file.
BufferedReader read=new BufferedReader(new FileReader("C:/eGurkha/agent/sample/UptimeRecord.txt"));
String line=read.readLine();
while (line != null)
{
System.out.println("lines are :"+line)
line=read.readLine();
}
By using the above code I can read all the line from the file, But I want to read from the some starting point.
For example : I have a file with 100 lines, from that file I want to read lines from 53 upto end of the file.
I need to modify the drawShape method to calculate the distance from the starting point (the diameter) of any shape regardless of how many sides I give it, but I have absolutely no clue where to begin with this. The ultimate goal of the program is to calculate the value of pi using the shape that is drawn.
Java Code:
public class PiTurtle extends Turtle
{
private double mySize;
private int mySides;
private double diameter = 0;
[code]....
I am working on a simple app that should emulate a desktop with some icons that you can drag around. I was instructed to use the MouseListener and MouseMotionListener. The icons should drag starting at the point where the mouse originally clicked down on it (ie not dragging from the top right corner).
I am drawing my icons to a jpanel, and I seem to be having two problems:The hitboxes are offThe icon is being dragged from the top right corner, despite having setup up a mouse offset at the beginning of the drag..Here are the relevant classes, the Desktop.draw() method is being called from my DrawPanel
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Desktop implements MouseListener, MouseMotionListener{
static DesktopIcon[] icons;
[code]...
Given the case I have an object which is assigned only once. What is the difference in doing:
public class MyClass {
private MyObj obj = new MyObj("Hello world");
private MyClass(){}
//...
}
and
public class MyClass {
private MyObj obj;
private MyClass(){
obj = new MyObj("Hello world");
}
//...
}
Is there a difference in performance or usability? (Given also the case there are no static calls expected) ....
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?
Given a reference variable : Car c1 = new Car();
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?
View Replies View RelatedHow 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?
What is variable shadowing?When does it occur?
View Replies View RelatedRegarding 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.
import java.io.*;
import java.util.Scanner;
public class SalesReport {
// private static double p1Total, p2Total, p3Total, p4Total;
private static double product1Total, product2Total, product3Total, product4Total, product5Total;
private static double person1Total, person2Total, person3Total, person4Total;
public static void main(String[] args) throws IOException
[code]....
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()) {
[code]....
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;
[Code] ....
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;
[Code] .....
How can I make variable from table value? Example:
Java Code:
String table [] = {"vara","varb"};
for(int i = 0; i < table.length; i++)
{
int table[i] = i;
} mh_sh_highlight_all('java');
And vara = 0, varb = 1 here.
Is this even possible?
i'm new withh java netbeans, and i want to make program where variable from database. how to get value from database to use in variable/
View Replies View RelatedI have a problem with my code. When, on strausParser class, i create the new object Beam i give him an array of Node object called "nodiestremi".
The problem is that when a Beam is created, the Beam created before take the Node of new Beam. Why it appends?
public class Main {
public static void main(String[] args) throws NumberFormatException, IOException{
SetFile.setupWindows();
Structure structure = new Structure();
}
public class SetFile {
}
I get an output like this:
Import node complete
0 0 0 1
0 1 1 2
0 1 1 0
0 2 2 4
Import beam complete
and not like this:
Import node complete
0 0 0 1
0 0 1 2
0 0 1 0
0 0 2 4
Import beam complete
My code has a method where the users input a bunch of variables and then those variables get added together in a new variable. What I want to know is how do I call the variable that is in the other method to another method?
import java.util.*;
public class Calc{
public static void main (String [] args){
determinevalue1();
determinevalue2();
determineTotalvalue(double value1, double value2);
[Code] ....