Create Two Instances Of Class And Test Each Of Methods
Nov 1, 2014
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
What I have to do: Use Applet to create two instances of the Employee class. Display the data on the Graphics object. Display in the applet the names and values of all of the instance variables in each instance of the class. Also display the value of any static variables.
What I'm doing:
import java.applet.Applet; import java.awt.*; public class EmployeeApplet extends Applet { public static int topSalary = 195000; int hoursPerWeek; public static void setTopSalary (int s) { if (s > topSalary)
[Code]...
I'm not able to display hours per week for e1 and e2.
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. */
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) {
Write a class encapsualting the concept of a course grade, assuming a course grade has the following attributes: a course name and a letter grade. Include a constructor, the accessor and mutator, and methods toString and equals.Write a client class to test all the methods in your class.
package labmodule7num57; import java.util.*; public class LabModule7Num57 { // Constructors//
For reference I am programming Java in BlueJ. I am fairly new to the language and I am having trouble with sorting.
I am trying to call / test all of the 5 sorting methods (at the same time) in the main class. To be specific, the sorted list has to technically outputted 5 times.
I figured out how to call / test Quicksort:
Sorting.quickSort(friends, 0, friends.length-1);
But the others are not working correctly. Specifically these:
For reference, this is the output when it is not sorted:
Smith, John 610-555-7384 Barnes, Sarah215-555-3827 Riley, Mark 733-555-2969 Getz, Laura 663-555-3984 Smith, Larry464-555-3489 Phelps, Frank322-555-2284 Grant, Marsha243-555-2837
This is the output when it is sorted:
Barnes, Sarah215-555-3827 Getz, Laura 663-555-3984 Grant, Marsha243-555-2837 Phelps, Frank322-555-2284 Riley, Mark 733-555-2969 Smith, John 610-555-7384 Smith, Larry464-555-3489
This is the class Sorting, which I should note is all correct:
public class Sorting{ /** * Swaps to elements in an array. Used by various sorting algorithms. * * @param data the array in which the elements are swapped * @param index1 the index of the first element to be swapped * @param index2 the index of the second element to be swapped */ private static <T extends Comparable<? super T>> void swap(T[] data, int index1, int index2){ T temp = data[index1]; data[index1] = data[index2];
[Code]...
This is the Main class in which I am supposed to call the sorting methods, SortPhoneList:
public class SortPhoneList{ /** * Creates an array of Contact objects, sorts them, then prints * them. */ public static void main (String[] args){ Contact[] friends = new Contact[7]; friends[0] = new Contact ("John", "Smith", "610-555-7384"); friends[1] = new Contact ("Sarah", "Barnes", "215-555-3827");
Declaring the method as static precludes one from using any sort of object oriented programming, thus the method cannot access instance fields of the object if it needs to.
I created two short classes to sort of find out what this meant, but I feel I do not understand it well enough.
Test class (main):
package votek; public class Test { public static void main(String[] args) { SomeMethod(); } public static void SomeMethod() { Character character = new Character(); character.totalLevel = 50; System.out.println(character.totalLevel); } }
Character class:
package votek; public class Character { private int level = 0; public Character() { level = 50; } }
OR
Does it mean that making a static method in the class with private instances will prevent the method from using the private instances?
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
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. {
I want to make several classes which extend different objects and add additional functions to simplify them and make their purpose in my projects more narrow and make their instances easier to use. So an example, Image class which extends BufferedImage and the constructor in Image class directly loads the file without having to create it first and then have to use Try Catch and all that additional code. Now, here is where my question comes in. Can I make an class, an abstract class or something which can be IMPLEMENTED into these several classes such as the Image class, and in doing so those several classes will have to have (like unimplemented methods) a HashMap<String key, ChildClass instance_as_value>, child class being the Image class as an example.
So I would have something like public class Image extends BufferedImage implements Library, and this class, because it implements Library will have a HashMap<String key, Image value> in it or it's parent class.
If i have a class(lets say class name is Approval) with the following private members: String recip_id, Int accStat, String pDesc, String startDate How can i create public get and setter methods for these private members of the class?
"Write a program (save the program as ProductInventory.java) that will read data about 5 products from a text file (Products.txt. The program should use the data read from the file to create instances (objects) of Product.java(Use Product class as a Reference Type)."
I'm yet to discover how I will get the info from the textfile using scanners but I don't know how to "create instances of a reference type".
This is the code of Product.java that came with the exercise.
public class Product { private String productCode = ""; private String productName = ""; private int quantity; private String supplierName = ""; private String supplierAddress = ""; private double price;
[Code] .....
By the way, the exercise also required me to use the abstract class ProductLister. To be clearer, the text file is kinda like this:
54643 Rizer Mouse Mark5s Merchandising Marquee Mall 4 205.50 23412 Acer Ultrabook JohnJade Merchandise Cornal City 2 62200.00 93112 Dell Ultrabook Octagon Marketing Cornal City 3 68900.00 22126 Macbook Air Pro Computerware Services San Beda, Chad 2 93500.00
Each numeric value in the file is an indication of the number of occurrences of each feature (e.g., forest, tree) multiplied by a given penalty. To generate instances from such a file, I use the following Java code:
I then add the so-generated instances to my model using the instruction model.addInstances(generatedInstances). The resulting output is described below.
It contains errors caused by the instruction model.addInstances(generatedInstances). Debugging my code showed me that the alphabet associated to the model is null. Am I using the wrong iterator?
The idea is pretty simple; extend StackPane, add an active property, bind the visible and managed properties of the pane to the active property, and, whenever the active property is changed to true, iterate sibling nodes de-activating any siblings that are also of the type Card.
However, this doesn't work with Scene Builder. While trying to debug, I created an ExtStackPane:
import javafx.collections.ListChangeListener; import javafx.scene.Node; import javafx.scene.layout.StackPane; public class ExtStackPane extends StackPane { { getChildren().addListener((ListChangeListener<Node>) c -> { System.out.println("ExtStackPane children change: " + c.toString()); }); } }
All this does is log list change events. However, I was very surprised by the output when working in Scene Builder. I added both controls to Scene Builder and did the following:
0) Added an ExtStackPane 1) Added a Card to the ExtStackPane 2) Added another Card to the ExtStackPane 3) Added a Label to the first Card 4) Added a Label to the second Card 5) Changed the text of the first Label to Hello 6) Changed the text of the second Label to World 7) Set the first Card to active 8) Set the second Card to active
I get the following output:
1) ExtStackPane children change: { [Card@5b9067b3] added at 0 }
2) ExtStackPane children change: { [Card@6b6328bd] added at 0 } ExtStackPane children change: { [Card@6aca8cc5] added at 1 }
[Code] ....
This is what things look like in Scene Builder:
Does Scene Builder recreate the entire hierarchy every time I make a small change? Here's an application that does the same as the manual steps I performed in Scene Builder:
import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.control.Label; import javafx.stage.Stage; public class CardApplication extends Application {
[Code] ....
The output when running the above is:
1) ExtStackPane children change: { [Card@6dfaa767] added at 0 }
2) ExtStackPane children change: { [Card@6aa2c411] added at 1 }
[Code] ....
The behavior is obviously a lot different than when I'm working with the control in Scene Builder. What Scene Builder is doing to change the behavior of my Card control so much? Does my Card control break some rule(s) I'm not aware of?
I have a class named Base and a private variable named _hopcount i have 10 instances of class base i use _hopcount as creteria to some if but other instances edit _hopcount so i want to prevent _hopcount edit by other instances; I want to have private variable which other instances of same class can't modify it.
public class Base extends TypedAtomicActor { private int _hopcount = 0; if(_hopcount <= 3) { some code; } public function() { _hopCount += 1; } }
public class Car { //instance variables ---------------------- private String make; private String model; private int year; private double vehiclePrice; private double downPayment; private double milesPerGallon;
[code]....
I created this class "Car" (also not sure if it's correct) and need to write a driver program that creates two instances of the class Car. One must use the default constructor, and the other must use the non-default constructor. It must demonstrate the methods used in the Car class using those instances.
public class DriverCar { public static void main(String[] args) { Car car1 = new Car("Toyota", "Corolla", 2013, 20000, 3000, 35); Car car2 = new Car("Ford", "Taurus", 2005, 14000, 1500, 25); System.out.println(car1);
I have to write a test class for a Contacts class called ContactTest and store the instances of Contacts created into a LinkedList.The ContactTest class should implement the addition andremoval of contacts to the Linked List and display its contents.
So far I have this, which stores the information entered into a Linked List, the problem is I don't know how I go about doing the addition and removal part.
Contacts Class
public class Contacts implements InterfaceContacts { String fname; String lname; String phone; String email; //constructors public Contacts( ){ this("****", "****", "****", "****");
In my programming class we need to create a large test array of Longs to iteratively sum/reverse the array and recursively sum/reverse the array.creating the array and where to go from there.
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?
From what i understand static methods should be called without creating an instance of the same class . If so why would they return an instance of the same class like in the following : public static Location locateLargest(double[][] a) , the Location class being the same class where the method is defined . I don't understand this , does it mean that every field and every method in the class must be static ? Meaning that you cannot have instances of the class because everything is static . Or it's just a mistake and the class Location cannot have a static method: public static Location locateLargest(double[][] a) ?
I have make the immutable class as below, Now my question is how I can test if my this class/object is immutable
package com.learning; import java.util.*; import java.util.Map.Entry; public final class ImmutableTest { private final int id; private final String name; private final HashMap<String, String> hm ;
[Code]...
How I can Test If it is immutable class without looking ?
How do you test a default constructor in one class and then test it in a different class? This is the code for the Person class which has the default constructor. I'm not sure in the PersonTester class how to access this default constructor and how to test it - what I have so far for the second class is also below.
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
