java com.brainbench.TestCommandLine -p Parameter1 Parameter2 Parameter3 Parameter4 ..
If the user enters the command line shown above, how many elements are contained in the array which is passed to "public static void main(String args[])" in TestCommandLine?
Choice 1 Four
Choice 2 Five
Choice 3 Six
Choice 4 Seven
Choice 5 Nine
what is different between void main() and public void main()
View Replies View RelatedWhat does void and static mean in the main method?
View Replies View RelatedI am making an application in java, inside static void main, i want to customize all buttons, text areas and want to put them on desired location inside application. I have tried to use setbounds but can not use it, how can i use it, or is there any other way or layout to make my application components customized layout.
View Replies View RelatedI believe I am on the right track but when I run the program I get an error that the class that I can't call on the method. I need to have what is selected in the JCheckBoxes added to the toppings array and I can't get that done what so ever.
Java Code:
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
public class PizzaOrderListener
{
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
[Code] ....
I have problems with private static void print section, something is missing? And in case 4, I want it to stop the program(end the loop) but it keeps going.
import java.util.Scanner;
import java.util.ArrayList;
public class Dogregister16 {
public static ArrayList<Dog> dogregister = new ArrayList();
private static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args) {
initiate();
[Code] ....
case 4:
System.exit(0);
System.out.println("Exit program");
}
}
}
}
I've got a problem in Eclipse. The below code is a part of my program, used for (re)starting a new game. The 'public static int' statement gives the error 'This method must return a result of type int'..
public static int playAgain(){
boolean validInput = false;
do {
System.out.println("Would you like to play a game? Please answer 'yes' or 'no'.");
String playAgain = input.next();
[Code] ....
I thought static methods could never use instance variables, because they wouldn't know which instance to look at.
From Head First Java, p. 284: "A static method is not associated with a particular instance - only the class - so it cannot access any instance variable values of its class. It wouldn't know which instance's values to use."
Now I was answering some mock exam questions from Cameron McKenzie's SCJA book, and I don't understand one of the options. On page 205, the last question has an option that says: "Instance variables ... are not visible in static methods, unless passed in as arguments." This option is supposed to be correct. Now... how does that work?
In singleton pattern just having a static field is not enough? Do we really need to have a private constructor?
I can have a static field and have a public constructor and still say it is singleton.
package Experimentation;
import javax.swing.*;
import java.awt.event.*;
public class SimpleGUI1B implements ActionListener {
JButton button;
public static void main(String[] args) {
SimpleGUI1B gui = new SimpleGUI1B();
gui.go();
[code]...
This is a program from Head First Java! since main is static it shouldn't be able to call non-static methods because statics do not use any instance variable values but in the above program we're call a non-static method go() how is it possible?
Why is the logic not correct with the method public static boolean containsColor(String color, Circle [] ca)? It only returns me only false values.
Java Code: public class Circle {
private double radius;
private String color;
public Circle()
{
radius = 1;
color = "red";
[code]....
For the below program what are the default values passed by the JVM in order to call main() method
class program
{
public static void main(String[] args)
{
System.out.println(args[0]);
System.out.println(args[1]);
}
}
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class array
{
public static void main(String[] args)
[Code] ...
Is there a way to write this, where, alpha is one array.
Write a program that declares an array "alpha" of 50 elements of type "double". Initialize the array so that the first 25 elements are equal to the square of the index variable and the last 25 elements are equal to three times the index variable. Output the array so that 10 elements per line are printed.
If I have an array of 50 integers, can I break that to read in lines of 10?
I am trying to make a 2d array that keeps track of comparison counts. what I have so far works ok but writes over the previous elements with 0. can't seem to find where I am re-initializing the previous elements.
//this is one of my fill sort arrays
public void fillSelectionArray(int index, long countSum) {
//rand = new Random( );
//for ( int i = 0; i < listsize; i++) {
selectionList[ index -1] = countSum;
// }
[Code] ....
I know I am missing something just not sure what.
in java why main method is always static in nature...
View Replies View RelatedI 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.
I have this class:
package model;
import java.awt.Color;
import shapes.Oval;
import shapes.Rectangle;
import shapes.Shape;
import java.awt.Container;
import java.lang.reflect.Array;
[Code] .....
And as it is now, the values are not being passed into the shapeArray array. If I "hard code" two shapes into the array in this class, everything works fine later on, but I do not manage to pass values into the array from the createShape() method. I tried several approaches, nothing works.
I am writing a program to take user input in order to create an array, then call a void method that will read in the numbers (from user's input) and fill the array.This method must use a loop to do this.(The array is to be passed to the void method as a parameter)
in theory, this should change the contents of the array, but without returning a result. Because it is a void method, the array is only passed through the method, not returned; Am I correct?How can I return the array and display it without having to change my method type?
Here is my code:
Java Code: package program7array;
import javax.swing.JOptionPane;
public class Program7Array
public static void main(String[] args) { // main method
int howMany = Integer.parseInt(JOptionPane.showInputDialog(null, // user decides how long array is
"How many numbers are there?"));
double [] numbersArray = new double[howMany]; // creating the array
makeArray(numbersArray, howMany); // calling the array
[code]...
I just kinda get stuck when it comes to passing values into constructors, using main method or static method functionality. In theory i kind of understand how it work but when i type it, it's totally different! I have to have a junit test too but i guess i could do that in the end.
I have attached the assignment. So, how to proceed with this:
public class Flight {
int flight_number, capacity, number_of_seats_left;
String origin, destination;
String departure_time;
double original_price;
[Code] ....
I'm working on a method that would parse the value of the array of object that I passed through a parameter. I would like to ask if making Object as a parameter is doable. Let's say I have a class Student and Teacher. I created a class the would handle the sched and name it class Schedule and extend this class to the Student and Teacher. Now I want to have a function that will accept an array of Schedule from either Student and Teacher, what ever object I will pass in the parameter. I know its easy to just make a method with a separate parameter of my classes but im looking for a more dynamic code.
class Student extends Schedule{
//variables here for student
}
[code]
class Teacher extends Schedule{
//variables here for teacher
}
[/code]
private void parseObject(ArrayList<Object> objct){
Schedule temp = objct.get(0);
//there is no error in this part
}
Now when i will try to use the function and pass a data, it will not accept since my parameter should be an array of object. How would I twist dis one?
ArrayList<Student> temp_student = new Array....
parseObject(temp_student); // it will not accept my parameter, how would i make it as an object
I am taking the Class Algorithms and Datastructures and got an assignment for Lab that really throws me off. The goal is to create an Array out of a given CSV file, implement several Methods that get the size of array, etc.
I am still stuck in the first part where the CSV has to be imported into the Array. My problem is that I need a mechanism that figures out the needed size for the Array, creates the array, and only then transfers the data from the CSV.
The list consists of the following wifi related values:
MAC-Adress, SSID, Timestamp, Signalstrength.
These are on the list, separated by comma. The Columns are each of these, and the rows are the four types of values making up the information on a certain wifi network.
The catch is, we are not allowed to use any of the following:
java.util.ArrayList
java.util.Arrays
and any class out of java.util.Collection.
So far I used the BufferedReader to read in the file and tried to implement the array, but I get an arrayindexoutofboundsexception.
Below is my Code (Its still an active construction zone):
public class WhatsThere {
public WhatsThere(String wifiscan) throws IOException {
}
public static void main(String[] args) throws IOException {
// WhatsThere Liste = new WhatsThere(String wifiscan);
String[][] arrayListe = new String[0][0];
[Code] ....
I am having a little trouble with a part of my Java assignment that needs to have linked lists in it.
I need to write a public method that takes an array of type object to load strings into a linked list.
When I insert: title, category, year, artist in 4 Strings And when I press "enter" i put those 4 in a array "large", and then when I can start a new music insert with 4 new string elements and add those in the large array..So: I have an array "large" with the length 19 (or so..)(max ~100 or so)Then I what to: get,in a new array "title",the elements:0,4,8,12,16 (from the large array) and put them in a scrollable list. And when I select one element in the title array I then whant to get 3 remaining elements from this. And put it in a array called selection.
So the "large" and the "title" arrays must be dynamically sizes... or be copied to a larger sized..
1 can it be done with arrays?
2 how do dynamically change the size of for example the array "title"?
3 how do I receive the elements 0,4,8,12,16 and so on, (to (
large.length-3) and add it to the title array?
What is the sum of the array ar elements after executing the following code?
int[] ar = {1,2,3,4,5};
for (int i=0; i<ar.length-1; i++)
if (i%2==0) ar[i]=i;
My professor says the answer is 12 i dont know how he got that answer
I cant get this code to work if wont find the right min and range and its printing out my max three times . This is what I got
public static void main(String[] args)
{
double [] Rainfall = new double[12];
Rainfall[0] = 77.4;
Rainfall[1] = 56;
Rainfall[2] = 61.8;
Rainfall[3] = 62.1;
Rainfall[4] = 57.1;
[Code] ....
I have two arrays
private ReservedBook[] reservedBooks;
private LibrarySystem[] libraryBooks;
The library array has two books and I want to copy one of them to the reserved books when you type in the ISBN
public void borrowBook(String ISBN)
{
int i = 0;
if(numberOfBooks < MAX_BOOKS-1)
{
if(libraryBooks[i].getBookISBN().equals(ISBN))
{
for(i=0;i<MAX_BOOKS-1;i++)
reservedBooks[i] = libraryBooks[i];
}
else System.out.println("There is no such book");
}
else System.out.println("You have reached the maximum number of allowed books");
}
It shows me error: incompatible types - LibrarySystem cannot be converted into ReservedBook. How can I fix it?