I will like to add to the questions about constructors and its this. I have a class A with a constructor, i have a class B which initialize the constructor. also i have a class C which needs a variable in class A but doesn't need to initialize the constructor of A. the question how do i access the variable of class A without initializing the constructor.
View Replieshow to get access from variables in a super class or a subclass. Here is what I got:
1) I have a super class that is in Jar file, I created a link in Eclipse, I know that the link is created correctly, I am going to concentrate just in one variable, so I don’t have to put all the code here firstName; in the super class(the one that is define in the path)
public class CommissionEmployee {
// Field descriptor #6 Ljava/lang/String;
private java.lang.String firstName;
in my class i have 6 argument constructor
Does a variable have public access modifier? if we can use it within the class and outside of the class then can i access a public variable as follows??
class mo
{
void display() {
public int a=9;
System.out.println(a);
}
public static void main(String[] args) {
mo m=new mo();
m.display();
}
}
ERROR:
It shows 6 errors :-O.
Error 1. illegal start of the expression
2. class,interface, or enum expected
So far I thought that setting superclass member variables as protected would allow the subclasses to access them using this. and that this was a good approach. However now after further reading am finding that actually these variables are better set as private and then accessed by the subclasses using public method (getters and setters) or constructor.
So my question is do you recommend setting them as private instead of protected and what would be the best way to access these variables from the subclasses ?
Class UserAssessBean{
private String username;
private int userid;
private ArrayList<ModuleBean> module;
--{get/set}--
[Code] ....
How can i access the getters/setters of module bean, when it was returned as array list in UserAssessBean?
Does child class gets a copy of the methods and variables of parent class?
public class test1 {
public static void main(String a[]) {
Child c = new Child();
c.print();
[Code] ....
why is the output 1?
I just want to be able to read type and weight in the Letter class I created (I created read out messages to check in the Letter class). I am able to read it with in the Mail class.
package org.mailprice.postage;
import java.util.Scanner;
public class Mail {
static Letter letter;
[code]....
This is my main.java:
import javax.swing.UnsupportedLookAndFeelException;
public class Main
{
public static void main(String[] args)
throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException
{
Core window = new Core("GAME1", 0, 0, true, true);
}
}
And this is my Core.java:
import java.awt.GraphicsEnvironment;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
[Code] ....
In Core.Java at line 80 how can I access window (
JFrame window = new JFrame(Game_Title); // <- this window
) ?
Also should I use throws or try and catch ?
I wanna know which is the best way to access a variables within a class ...
Using direct access or using the variable accessor ...
Example :
public class Numbers{
private int n1;
private int n2;
public void setN1(int n){
n1 = n;
[Code] ....
How can I access to a jLabel of a class from another class or edit its text?
View Replies View RelatedI have 2 classes. TestClassA has 1 getter and 1 setter. From my second class, TestClassB, I want to access the getter method of TestClassA. If I try to access it, I get null. How do I do it?I do not want the methods to be declared as static. How can the getter method value be printed in TestClassB (without marking anything as static)?
public class TestA {
private String name;
public String getName() {
return name;
[code]....
I've been unable to figure out how to access an objects data from another class. I ended up missing a lesson in java and haven't been able to catch up on this topic on my own through my textbook.
Error: has private access
Code:
public class TestCoffeeDrinker {
public static void main(String[] args) {
Coffee latte = new Coffee("Starbucks Tall Latte", 2.85);
Coffee mocha = new Coffee("Starbucks Grande Mocha", 3.95);
Coffee mcdonalds = new Coffee("McDonalds McCafe", 0.99);
System.out.println(mcdonalds.toString());
[Code]...
why I cant access a variable from another class, in particular why in the main class cant i assign " quiz1 = getQuizOne();" ? It constantly giving me error.
Java Code:
import java.util.Scanner;
public class Grade {
private int quiz1, quiz2, midtermExam, finalExam = 0;
public static void main(String[] args)
{
Student John = new Student();
John.StudentData();
[code]....
I make a coding a subject system for my internship project, I use JComboBox to choose name of faculty. I want to call selected item of faculty from another class to choose subject under the selected faculty.
How can I call selected item from another class?
This is my coding for select faculty.
public class lectInterface(){
private void saveDataActionPerformed(java.awt.event.ActionEvent evt) {
String staff_id=staffID.getText();
int staff_Id=Integer.parseInt(staff_id);
String Name=staffName.getText();
[Code] ....
and below is coding for another class
try{
LectInterface lI = new LectInterface();
String host = "jdbc:derby://localhost:1527/STUDLECDB";
String uName = "studlecdb";
String uPass = "studlecdb";
Connection con = DriverManager.getConnection( host, uName, uPass );
[code]....
I have a linked list of objects of a class I created called BaseballPlayer. I also have a Fielder and Pitcher class that extends BaseballPlayer. The linked list and list nodes accept elements of type BaseballPlayer. I put into the linked list both Fielder objects and Pitcher objects. The Pitcher class has a method that returns a float variable that is only found in the Pitcher class called EarnedRunAverage. However, in my main program it won't let me access the method. It says: The method getERavg() is undefined for the type BaseballPlayer. It does however, let me access methods in the super-class BaseballPlayer.
Here is main code and the Pitcher class code.
ListNode p = list.getFirst().next;
while(p!=null){
if(p.player instanceof Fielder){
sortedFielders.append(Integer.toString(p.player.getNum()) +',');
[Code]....
Why can't I access a method from another class? For example, I want to get the value of get method from another class. It's giving me an error on if(getExamType() == 'M') That's what I've done, for example:
Java Code:
public static Exam[] collateExams(Exam[] exams){
Exam [] r = new Exam[50];
r = exams;
Exam [] finalExam = new Exam[50];
for(int i = 0; i < r.length; i++) {
if(getExamType() == 'M') {
}
}
return r; mh_sh_highlight_all('java');
This time I have to make a Black Jack game ( I guess this is a classic) I have created Three classes for this BlackJack( Main), Card, and Player.
What I am trying to do is put the Give one card to the player and remove it from the deck into a separate procedure because I will be doing this several times during the game.
This is the code I have so far Under the class BlackJack.
Java Code:
package black.jack;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;
[Code] .....
While playing with arrays I've written this code:
import java.util.Arrays;
import java.util.Comparator;
class SimpleHolder extends Object {
private final int value;
public SimpleHolder(int value) {
this.value = value;
[Code] ....
According to The Java Tutorial, static nested classes should not have access to other members of the enclosing class. I'd suppose to get compile-time error in the BasicComparator class. However, my code compiles just fine. Am I missing something?
I have two classes built for this assignment. One with getters, setters and constructor and a test class. The test class works fine up until the point when the user wants to (M)odify an employee that he/she built with the loadEmployee method. What happens is I need to enter multiple "M" inputs before anything pops up, and when something pops up, it's the displayMenu instead of modifyEmployee method. I imagine it has something to do with the amount of sc.nextLine()
import java.util.Scanner; // utilize scanner via console
import java.text.NumberFormat; // allows numbers to be format in form of currency
//Example of "big loop" in main to repeat using a No Trip (0,N) test first
public class EmployeeTest {
// space provided to make code easier on eyes...
[code]...
This program should create a GUI that has 5 classes together on a grid layout. The problem that I am having is that the user input class has the input for kwh, hours, and gallons. I am having problems getting that information from the user input class to the totals class.
user input class:
package applianceutilitycalculator;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Scanner;
import javax.swing.*;
[code].....
The totals class should take the info from the kwh hours and gallons and do the math to get a total and display it in a JTextField(?).
When creating a class with a constructor, why does one have to create private variables (attributes) to be used as parameters by the object? The object's parameters will be set to be exactly equal to the private variables (attributes), so what is the point of having the private variables (attributes) Why are both private variables (attributes) and parameters needed when they are set to be equal each other anyway?
View Replies View RelatedI write a small program. I want post my integer variables in the next class. Here a code(I wanna change answer color):
Main class(pagrindine.java):
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
//Mokinio rinkinukas su skaiciofke kur gali keisti atsakymo spalva, pabandyti sukurti uzrasu knygute.
[code]....
So, I want to post variables r,g,b from class slideris.java in the pagrindiness.java.
if I declare
class Example
{
int x=10;
......
}
It is not showing any error but when I declare
class Example
{
int x;
x=10;
............
}
it showing compile time error ....
I am new to java. While compiling the "moooooo" program an error is displayed.
Error -- error while writing MooseGreetings :MooseGreetings.class
<access denied>.
What to do?
I have been asked to write a program with 3 classes(an interface, a store and a product class) and I have been going ok until I need to display data on the interface that is held in the product class. At the moment the code will compile fine but when I run the program and try to use the writeOutput() method I get a stack overflow error.
I realise now that it is because of a non-terminating recursive call, however I can not think of a solution on how to fix the problem. And just to clarify, what I am aiming to do is have the MatesTerminal class display the data for name that is stored in the Product class(I have no way of determining which product to display at this time, so I would like to be able to display the data for all three products if possible). Anyway this is what I have so far:
The method from the MatesTerminal Class:
private void writeOutput() {
int productChoice;
Scanner console = new Scanner(System.in);
[Code].....
I am having hard time to grasp the concept of java as i am beginner. according to different sources found in internet, only one class is written in one source file. and all those class can be accessed through the main class.
my question is
1.can we access one class present in one source file, through another class present in another source file [not through the class containing main method]?
2.can we create more than 1 class in same source file?is there special way to do it? i do get error always when i try to do so
3.can multiple classes contain main method? or should there be only single class containing it?