Suppose you have an abstract class say Sparrow that extends the abstract Bird class. The abstract Bird class has the abstract methods, fly() and run()
How many methods from the Bird class should you implement in the Sparrow class?
I am puzzled by a note in the book I am reading (by Mala Gupta). Page 55 says "All java components you've heard of can be defined within a java class: import and package statements, variables.....". But the online oracle doc (tutorial) clearly says the following 2 statments:
"If present, package statement must be the very first line in a file"
"To import a specific member into the current file, put an import statement at the beginning of the file before any type definitions but after the package statement, if there is one. " (Here).
So, how can import and package be present inside a class ? (This seems to go against the 2 statements from oracle online tutorial).
How do you declare methods for a class within the class whilst objects of the class are declared else where?
Say for instance, I have a main class Wall, and another class called Clock, and because they are both GUI based, I want to put a Clock on the Wall, so I have declared an instance object of Clock in the Wall class (Wall extends JFrame, and Clock extends JPanel).
I now want to have methods such as setClock, resetClock in the Clock class, but im having trouble in being able to refer to the Clock object thats been declared in the Wall class.
Is this possible? Or am I trying to do something thats not possible? Or maybe I've missed something really obvious?
I am working on some enhancement on application. I have a requirement. The flow is as below
In a jsp file one selection dropdown exists and a body. Selection dropdown is written as custom tag library and is included in jsp file eg tag.tld whose code exists in tag.java code for other parts of jsp are written in that *.jsp file itself. eg test.jsp
i.e test.jsp calls tag.tld to include selection dropdown
I now want a hashmap created in tag.java to be available in jsp file and I want to use it in one of the javascript function available in same jsp file for validation
How can I achieve this....
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 am working on a program that simulates a bug moving along a horizontal line, My code works correctly when I test it in it's own class but when I tried testing my constructor and methods in a test class I received an error saying, "package stinkBug does not exist" on lines with my methods. However, stinkbug is not a package.
Java Code:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
[code]....
Write a class named Calculator add four methods to that class:
add(int a, int b)
sub(int a, int b)
mul(int a, int b)
div(int a, int b)
Then write a Tester class with main function and show the use of the methods in Calculator class..
<input type="text" name="test" class="form-control input-sm" maxlength="20"/>
This is my textbox can i include in my tetxbox that it will no accept special characters?
Can i configure it there? like maxlength="20" w/c is character limit is set to 20, not allowing special characters be configure like that , character="speical is not allowed" something like that?
I have an fxml page with a TabPane element with two tabs tabOne and tabTwo:
<BorderPane fx:controller="lc.controllers.ControllerOne" xmlns:fx="http://javafx.com/fxml">
<center>
<TabPane fx:id="tabPane">
<tabs>
<Tab fx:id="tabOne" closable="false">
<text >ONE</text>
[Code] ....
As you can see above tabTwo has a separate fxml included within.
Now some of the tab content in tabTwo needs to be refreshed based on the actions performed in tabOne. But however initialize method of included tab action class is called only once for the first time when the fxml page loads. How the initialize method of tabActions.fxml can be forced to execute every time the tab loads?
I have created a standalone project and included its jar file in lib folder as follows :
Sample->lib>jar files
sample->src->source files
After constructing my Sample application jar file as sample.jar and trying to include it in my another web project as follows:
WebSample->WebContent->WEB-INF->lib->sample.jar
and constructed war files as WebSample.war
After deploying it is not able to access jar files of sample application and throwing NoClassDefFoundError. Where as if I am running it as standalone project it is working. What is best solution to resolve this issue.
import java.util.*;
public class SumOfAllEvens {
public static void main (String[] args) {
Scanner s = new Scanner (System.in);
//for (int i=1; i<4; i++){
int usernumber;
[code]....
I'm supposed to use a for loop that runs until it reaches the number input by the user, but I'm not sure how to tell the program to add the user's number along with all of the even numbers in between the user input and 2.
im trying to make a linear search method to check if a number 'n' is included in an array.
PHP Code:
package test;
public class Recursion {
public static void main(String[] args) {
}
static int linearSearch(int n, int[] array)
[code]....
Im getting the following error: this method must have a result type of type int ?? i already have a return type of type int...
We know that all classes in Java extend the Object class. But methods in Object class are declared as public.I think if they were declared as protected, then also there wont have been any issue. So, what is the reason behind making them as public?
View Replies View RelatedIs it possible to have multiple methods in one class?And can I use the Scanner in methods other than the main method?
View Replies View Relatedthere are two classes here. I need to put the max and min methods should be in the tester class, but I have tried moving it to the tester class and it will not comply. When I run I get a list of errors of "Error:(43, 9) java: illegal start of expression
Error:(43, 16) java: illegal start of expression
Error:(43, 22) java: ';' expected
Error:(43, 41) java: '.class' expected
Error:(43, 52) java: illegal start of expression
Error:(43, 51) java: not a statement
Error:(43, 53) java: ';' expected
Error:(57, 9) java: illegal start of expression
Error:(57, 16) java: illegal start of expression
Error:(57, 22) java: ';' expected
Error:(57, 41) java: '.class' expected
Error:(57, 52) java: illegal start of expression
Error:(57, 51) java: not a statement
Error:(57, 53) java: ';' expected"
package A808;
public class FuleTesterV1
{
public static void main(String[] args)
{
String titleLines;
titleLines = "Yearly Gas Mi Calc | Assignment 8.08";
String TitleLines;
TitleLines = "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~";
[code]....
I am wanting to override certain methods in some Minecraft class files, and tell those class files to use code from my class files.
And no, I don't mean extend a class. When I try to extend from the main Block.Class, it makes that file as another block file for the game, or something.
So like, I want to tell the main file that handles block registries to use the code from my class file to register my custom blocks to the list of blocks, but without modifying that main block file.
Is this even something that's possible?
Also, I know that the way a file is named affects the loading order. My class files would be named using symbols to make it load right before the class file I want to override.
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]...
So in the code below I create an instance of my own triangle class and use one of its methods. The thing is I use one of my triangle classes methods in a method other the main method of my main program so I'm thinking it can't access it?
Any way here's the code for my triangle class
import java.util.Scanner;
public class QudratullahMommandi_Triangle_06 {
Scanner keyboard = new Scanner(System.in);
private double side1;
private double side2;
private double side3;
[Code] ....
and here's the error message
QudratullahMommandi_S_06.java:46: error: cannot find symbol
{ triangle1.outPut();
^
symbol: variable triangle1
location: class QudratullahMommandi_S_06
1 error
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 trying to get the average of 3 different fraction arrays. I made a fraction class and I made methods such as read() and average() in this new class.
package fractions;
import java.util.Scanner;
import java.util.Arrays;
public class FractionArrays {
public static void main(String[] args) {
Fraction completeFraction = new Fraction(5,6);
[Code] ....
I was wondering if there was any way to use the arrays I created in the read method in the average method. If I find that out I should be able to do it on my own. Is there a way to make the arrays public to use in different methods?
Okay, so I have to create a class with instance data and instance methods.
First, BankAccount class. It should contain the following information, stored in instance variables:
First name: The customer's first name.
Last name: The customer's last name
Balance: The amount of money the customer has in the account.
It should have the following methods:
BankAccount(String firstName, String lastName,
double openingBalance)
This constructor creates a new BankAccount
public String firstName()
Returns the customer's first name
public String lastName()
Returns the customer's last name
public double balance()
Returns the customer's account balance
Finally I need to create a driver to test my class. And create several accounts and verify that the first name, last name, and balance methods work properly. This is my code below.. I don't know if I did it right.
public class BankAccount {
String firstName, lastName;
double balance;
public BankAccount(String firstName, String lastName, double balance) {
[Code] .....
The one problem in my book was to create a constructor for different shirt features, which I did and ran successfully. Out of curiosity, I also added other methods to see if it would run if the parameters were different from the constructor. It keeps giving me a constructor error. So, my question is, am I able to create a class that uses a constructor with parameters and other methods without errors? I'm guessing there's no reason to since it would be wasted space since the constructor could do it but was just curious if it's possible.
Is everything from the constructor down (in the class) and Shirt.oneShirt (in the main) just a waste of time?
Here's my example:
public class Shirt//class name.
{
int collarSize;//data field.
int sleeveLength;//data field.
int pocketNumber;//data field
public final static String MATERIAL = "cotton";//final data field for material.
public Shirt(int collarSize, int sleeveLength, int pocketNumber)//start of constructor.
{
[Code]...
So I've been working on this sphere class forever and have tried rewriting it a number of times. each time i change something i get a different error...
Instructions: create a sphere class with the following properties:
private attributes: x, y, z coordinates of center, and the radius.
Accessor and mutator methods to: set and get the x,y,z coordinates, set and get the radius, get the volume and surface area of the sphere.
This is the main sphere class:
Java Code:
package spheretester;
<pre class="brush:java;"> */
import java.io.*;
import java.util.Scanner;
public class Sphere {
public static void main(String[] argv) throws Exception
[Code] ....
I am to create a Array class then create a Driver class (TestArray) to test all the methods in the Array Class. Here's the code i've written for the Array Class. I just nee developing the TestArray class.
import java.util.Scanner;
public class Array
{
Scanner sc = new Scanner(System.in);
private double[] array = new double[];
public void setArray(double[] arr) {
[Code] ...
How do I use two constructors and I'm having trouble with using char for gender...
Write a program to test the Person class defined below. Your test program should create two instances of the class (each to test a different constructor) and test each of the methods. You are also required to illustrate the error in trying to access private data members from the client class (for clarity temporarily change the private modifier to public and test again). See screenshots below for sample output.
The screen shots are displayed as:
p1 name = Not Given Age = 0 Gender = U
p2 name = Jane Doe Age = 0 Gender = F
p1 name = John Doe Age = 25 Gender = M
and
PersonTester.jave:20: name has private access in Person
System.out.println("p2 name = " + p2.name + "Age = " + p2.age + "Gender = " + p2.gender);
PersonTester.jave:20: age has private access in Person
System.out.println("p2 name = " + p2.name + "Age = " + p2.age + "Gender = " + p2.gender);
PersonTester.jave:20: gender has private access in Person
System.out.println("p2 name = " + p2.name + "Age = " + p2.age + "Gender = " + p2.gender);
3 errors
Here is the class given :
class Person {
// Data Members
private String name; // The name of this person
private int age; // The age of this person
private char gender; // The gender of this person
[Code] .....
What is the name given to two (2) or more methods in a class with the same name but different parameter/ argument lists?
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