How To Get Access From Variables In Super Class Or Subclass

Dec 2, 2014

how 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

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Superclass Variables - Subclass Access

Apr 13, 2015

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 ?

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Super Keyword When Used Explicitly In A Subclass Constructor

Jul 9, 2014

The super keyword when used explicitly in a subclass constructor must be the first statement but what about if i have a this(parameters) statements ? As the this one must also be the first statement... Does this means that i can have only one or the other ? What about when the super constructor is not explicit (aka implicit ) , can i use the this( parameters) in the same constructor ?

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Set Methods In Super And Subclass By Using Dialog Boxes

Nov 7, 2014

I am creating a set of 3 subclasses, 1 superclass, and an application. In my instructions it says to make set methods in my super and subclass by using dialog boxes. In the application you have 3 different arrays where you create objects and are supposed to call the methods from the subclasses to be used in the application. I don't know how to make the dialog boxes from my subclasses to show up in my application.

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Access To Variables In Another Class?

Oct 4, 2014

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.

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Subclass Access From Client?

Oct 2, 2014

I am trying to prepare for the next installment Java course. I found a syllabus online from last year. All I'm trying to say is that I am not in this course but will be shortly. I tried the first project but I am having subclass issues. I want to access the getStock method in the Executive subclass from the client. I keep getting a cannot find symbol: method getStock from class Employee. I don't know why won't access Executive.

Main:

import java.util.*;
public class EmployeeClient extends Employee {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
//variables
String name = " ";
int totalSalary = 0;
int stock = 0;

[code].....

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Create Unique Constructors And Variables For Every Subclass

Sep 10, 2014

I have a class called Sprite which extends its several subclasses. Therefore, there are a lot of different Sprite classes, the thing is however, most of those subclasses have unique types of variables which I want to only be included in those particular subclasses, not anywhere else. For instance, I might have a variable measuring distance in one subclass, and in another subclass there might be a height variable inherent. I don't want the first subclass to have both variables, neither the second or the main class. Because before I initialize my subclasses, I need to create the constructors of those subclasses in the main Sprite class first because it doesn't have the unique variables which those classes consist of. How do I prevent that? Now I have to create the unique constructors and variables for every subclass, when I only want them in their associated classes.

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Inheritance Super Variables - Fail To Return Null

Aug 13, 2014

I'm writing a simple program in which I have a super class Person, inherited by the subclasses Customer and Employee (they inherit the variables ID, name and surname).

Java Code:

public class Person {
int id;
String name;
String surname;
public Person () {

[Code] .....

However the problem is here: when I try to get the variables ID, name and surname through my main class, they fail to return (0,null,null). Why is this? I have get-Methods in my subclasses which should return the super variables, but they are not.

Java Code:

public String getUser() {
return username;
}

public String getName() {
return super.name;
} mh_sh_highlight_all('java');

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Indexing Each Subclass Of Certain Class

Jul 3, 2014

I have a problem where I want to give each subclass of a certain class an index number (I don't care what index numbers are given, as long as there is a one-to-one relationship between subclasses and index numbers and the index numbers don't skip). This number will be used to sort the subclasses as an intermediate step to what I want to achieve. I know I could do this:

interface Superclass {
int index();
}
class Subclass implements Superclass {
int index() {
return 0; //or 1, or 2, ...
}
}

But this quickly gets tedious when I'm looking at lots of subclasses. Plus, there's the off chance that I could mess up and assign an index twice to two different subclasses by accident. Is there a better way to do this? I read about Annotations.

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Passing Value From Sub Class To Super Class

Oct 19, 2014

So the first thing we did was make a program called memory calculator. now we are supposed to make a sub class that modifies the program to also do exponents and natural logs. Then to make a new class that acts as the driver for what is now called the scientific memory calculator which includes the exponent and log. I have watched this through debug and im a little confused. first off it creates a variable for currentValue in current and in sci which are my instances, which i dont think is what i really want to do, I am unsure how to get the things in the Scientificmemcalc to do stuff without calling them directly. so when i try to do the power feature it does everything correct but it sets the sci current value to the correct answer, and now i cant figure out how to pass it on to the current current value.

This is the memory calculator :

public class MemoryCalculator {
public static void main(String[] args) {
MemoryCalculator current = new MemoryCalculator();//creates an instance
int choice = 0;
do{//main loop
System.out.println("Current value: " + current.getCurrentValue() + "

[Code] .....

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Super Class - Getting Error Identifier Expected

Aug 9, 2014

I created a superclass Ships and under that a class CivilShips. Under that HumanBulkFreighter.

I declared variables in Ships and CivilShips and wanted to have them set in HBF to a specific value. When I know try to compile them I get the following:

HumanBulkFreighter.java:2: error: <identifier> expected
cargo=1500;
^
HumanBulkFreighter.java:3: error: <identifier> expected
size=200;

[Code] ....

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Why Super Classes Always Declared As Interfaces And Not Abstract Class

Dec 1, 2014

While reading the design patter book, i got one doubt ,There is a List an interface having sub classes ArrayList, LinkedList etc.,

Q1) My question is Why they declared the List as interface rather than Abstract class?

Q2) i read some site -

List l = new ArrayList(); Why it is GOOD line?
ArrayList l = new ArrayList() ; Why it is BAD line?

Answer required with detailed information for Q1 and Q2.

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Access Modifiers For Variables

Aug 15, 2014

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

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Access Getter / Setter Of Bean Class Where It Defined As Member In Another Class?

Feb 18, 2014

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?

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Inheritance In Java - Child Class Get Copy Of Methods And Variables Of Parent Class?

Mar 1, 2015

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?

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Reading Variables Class To Class

Feb 3, 2014

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]....

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How To Access JFrame From Another Class

Oct 9, 2014

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 ?

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Accessing Variables Within A Class?

May 19, 2013

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] ....

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Swing/AWT/SWT :: Access JLabel From Another Class

May 6, 2014

How can I access to a jLabel of a class from another class or edit its text?

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How To Access Getter Method From Different Class

Sep 16, 2014

I 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]....

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How To Access Objects Data From Another Class

Oct 3, 2014

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]...

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Cannot Access Variable Form Another Class

Jul 24, 2014

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]....

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How To Access Combobox From Another Class In Netbeans

Aug 17, 2014

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]....

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Cannot Access Function Of Extended Class

Apr 21, 2015

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]....

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Why Cannot Access A Public Method From Another Class

Feb 12, 2015

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');

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Access A Method Of Class From Main

Feb 9, 2014

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] .....

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