I have been writing test scripts for my class but I'm stuck on this method. how do i test for an object?
@Override
public boolean equals(Object obj) {
if (obj.getClass() != Fraction.class)
return false;
return (this.toString().equals(obj.toString()));
}
I'm trying to find all of the prime factors for a given number. The following code achieves this:
private static ArrayList<Long> findPrimesOf(long number) {
ArrayList<Long> primes = new ArrayList<>();
long highestDivisor = (long)sqrt(number);
for (long divisor = 2; divisor <= highestDivisor; divisor++) {
if (number % divisor == 0) {
boolean isPrime = true;
for (long i = 2L; i < divisor; i++) {
if (divisor % i == 0) {
isPrime = false;
break;
[code]....
However, if I remove the boolean test isPrime, as below, I get additional numbers after the highest prime factor.
private static ArrayList<Long> findPrimesOf(long number) {
ArrayList<Long> primes = new ArrayList<>();
long highestDivisor = (long)sqrt(number);
for (long divisor = 2; divisor <= highestDivisor; divisor++) {
if (number % divisor == 0) {
for (long i = 2L; i < divisor; i++) {
if (divisor % i == 0) {
break;
[code]....
I can't work out why this should be. From my understanding, the divisor only gets added to the list of primes if the loop doesn't break (which, with the boolean test would be true anyway).
Here is my code the whole program is working correctly but the Boolean equals and the has code and it is a requirement for the assignment. Why it is not working.
I know there are issues with the code I am new with java and was struggling so I have to clean my code up before I submit the assignment but for right now I have the out put the way I want it except the Boolean and hash code methods always output that the rectangles aren't equal even when I know they are and it outputs the not equal statement twice??
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.Scanner;
[Code] ....
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 ?
I am currently trying to use Junit to test a whole bunch of stuff. I almost have full line coverage but I am getting hung up on testing an if statement that consists of whether or not an object is an instance of another class. This class happens to be an interface, and even the object is an interface. Weird I know but I just want to know how to get into that if statement. I realize testing interfaces might be a waste of time but I still really want to know how. Here is an example of what I am trying to test:
Java Code:
if(x instance of y){ //where x and y are both interface objects
doSomething();
} mh_sh_highlight_all('java');
I read in a book that when you change the value of a method parameter that's a boolean or other basic datatype within the method it only is changed within the method and remains the same outside. I want to know if there is some way for me to actually change it within the method. For example:
public class Change {
void convert(boolean x, boolean y, boolean z) { //i want to set x,y, and z to false in this
x = false;
y = false;
z = false;
[code]...
I want to put in part1, part2, and part3 when i call the method than i want them to be set to false within the method. The specific reason i asked this question was because im trying to code a battleship and i have a subroutine class with a method that when its called it checks if a ship has been sunk. If the there was a sink than the method will set a ton of boolean variables to false.
Just to clarify, I want something like this:
void convert(thing1,thing2,thing3,thing4) {
//some code here that sets thing1,thing2,thing3, and thing4 to false
}
// than in main:
boolean test1 = true;
boolean test2 = true;
[code]....
I am trying to test the instanceof keyword. To do this, I've made a method with a simple logical test like so:
Java Code:
Vehicle vehicle1 = new Vehicle();
public void Type(){
if (vehicle1 instanceof Vehicle) {
System.out.println("Type = Vehicle");
}
else if (vehicle1 instanceof Car) {
System.out.println("Type = Car");
}
else if (vehicle1 instanceof Truck) {
System.out.println("Type = Truck");
}
}
} mh_sh_highlight_all('java');
I wanted to try implementing it into the class definitions for Vehicle, then extend that to Car and Truck, but I'm not sure how to use this test in a general case.
The only way this method works is if I set the test to specifically accept a specific object as a parameter.
I want to test multiple objects, but I'm not really sure how else to do this without simply copy-pasting the logical test multiple times and changing the respective objects that are used as parameters.
Java SE Runtime Environment build 1.8.0..This is part of the code:
public static int addAddress (String[] number, boolean[] front, double[] total) {
int num = 0;
double ffee = 0;
/*boolean value = false;*/
[code]...
I have tried using the line of code commented out, /*boolean value = false;*/. However, another error is displayed. The compiler shows the following...
Inspection.java:33: error: incompatible types: boolean cannot be converted to boolean[]
front[num]= defineFront(num, value);
^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output error...I know that boolean values are by default stored as false, once you create the array. However, I'm having trouble passing the variable to the method.
I am working on a program that simulates someone logging in. For this program, I have three methods:
public void input(String text)
public void click(String button)
public boolean loggedIn()
Naturally, the default status of loggedIn() is false, but I am having trouble changing the boolean to true when a user has successfully entered a username and password.
Specifically,
public void click(String button) {
Button = button;//Button is declared at the beginning of the class
if(Button == "Submit") {
//Statement that changes loggedIn() from false to true when the user clicks the "Submit" button.
}
No matter what I try, I get various errors about how what I tried was illegal.
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]....
Write a static method odd() that takes three boolean inputs and returns true if an odd number of inputs are true, and false otherwise.
View Replies View RelatedI've been trying to program a software for minimizing (sum of products and products of sum) a boolean algebra using Quine mccluskey method... I've created the GUI and I got stuck in the process... I need a code for minimizing a 10 variable function ....
View Replies View RelatedI'm having trouble setting up a test for my combination method.Here's the method (It basically finds the most amount of characters that both substrings share and combines the two using the number of shared characters as a breaking point):
public static String combination(String str1, String str2, int overlap) {
assert str1 != null : "Violation of: str1 is not null";
assert str2 != null : "Violation of: str2 is not null";
assert 0 <= overlap
&& overlap <= str1.length()
&& overlap <= str2.length()
&& str1.regionMatches(str1.length() - overlap, str2, 0, overlap) : ""
+ "Violation of: OVERLAPS(str1, str2, overlap)";
[code]....
I had to write a class called Thermometer, that has one instance variable (an integer) for the temperature in Fahrenheit. I had to include the following methods
-a constructor that initializes the temperature to 60
-there is a method to change the temperature
-there is a method to display the temperature
-there is a method to reset the teperature to 60
Here is the code for that.
public class Thermometer {
private int temp;
private int thermometer;
public Thermometer() {
thermometer = 60;
[code]....
Now I get to the issue. I have to write a test class called thermometer to test the thermometer class. I need to test each method while displaying the temperature after it. My professor said I should use the invoke method but didn't go into much more detail than that.
This program contains a superclass and a subclass that will gather the following information from the user:
name, address, phone number, and customer number.
Everything works fine except that I have to create a boolean method in this program that is required to determine based on user input whether they want to be added to a mailing list.
I cannot get this method to work with main, each time it is called it will always return the value but main will constantly read the last statement (else, where it will read "not wanting to be added to the mailing list).
The only way I can get this part of the program to work is by adding an equals method in main that ignores the case, but I am required to write a boolean method so this is not allowed.
Superclass:
public class Person
{
private String name;
private String address;
private String phoneNum;
public Person(String pName, String add, String number)
{
name = pName;
address = add;
[Code] ...
Write a class encapsulating 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.
how to test and finish the toString and equals method in this code ?
package labmodule7num57;
import java.util.*;
public class LabModule7Num57 {
// Constructors//
private String name;
private String letterGrade;
public LabModule7Num57 (String name,String letterGrade) {
[code]....
Create an equals method that takes an object reference and returns true if the given object equals this object.
Hint: You'll need 'instanceof' and cast to a (Geocache)
So far I have:
public boolean equals(Object O){
if(O instanceof Geocache){
Geocache j=(Geocache) O;
if (this.equals(j)) //I know this is wrong... but I can't figure it out
return true;
}
else return false;
}
I think I have it correct up to the casting but I don't understand what I'm suppose to do with the this.equals(). Also I'm getting an error that I'm not returning a boolean... I get this all the time in other problems. I don't get why since I have to instances of returning booleans in this. "returns true if the given object equals this object" makes no sense to me. I assume the given object, in my case, is 'O'. What is 'this' object referring to?
I am trying to run a class with a client code and I get the following error
The method add(TimeSpan) is undefined for the type TEST
Why i get this error?
package timespan;
// Represents a time span of hours and minutes elapsed.
// Class invariant: minutes < 60
public class TimeSpan {
private int hours;
private int minutes;
[Code] ....
Which method is used while passing or returning a java object from the native method?
View Replies View RelatedI've been trying to learn Java for the last 36 hours or so (after applying for a HTML/CSS job saying "Java knowledge preferred"), and decided to experiment a bit making a graphical tic-tac-toe game. I eventually managed to get that done and it's working. Working code below:
[Java] tic tac toe 1 - Pastebin
So, it works to an extent, however, the way I am capturing which cell is selected seems very sloppy, and would not work if the cells weren't squares or rectangles. So I made a copy of the project and restructured it adding the mouse event to the cells, but now I can't get JComponent to repaint. New code below:
tic tac toe 2 - Pastebin
Curiously, clicking triggers the action for all 9 cells, but I presume it's because I haven't bounded them making it think I've clicked all 9 simultaneously.
What I've tried:
Make the Cell class extend the game class and call this.repaint()- causes stack overflow.
Calling Game.GameState() within the cell clicking event and making that function static - compiler doesn't like calling repaint() inside a static function.
Making another class to make a clone of the Game object and then refresh- was never going to work....
I read the following comment at stackoverflow.com. It is not clear to me why equals in the code below does not override - i looked up Object class equals() and the signature is same.
public class Foo {
private String id;
public boolean equals(Foo f) { return id.equals(f.id);}
}
This class compiles as written, but adding the @Override tag to the equals method will cause a compilation error as it does not override the equals method on Object.
I am getting this error "Type mismatch: cannot convert from Object to E" in the last line of the pop() method.
package stack;
public class Node<E> {
E item;
Node next;
Node(E item) {
this.item = item;
this.next = null;
}
[code]....
I don't understand why that error occurs despite item being declared as type E in the Node class.
I don't know why class Object have two PROTECTED method -- clone() and finalize(). And in JUnit's source code, I notice that kent write :public class AClass extends Object {}I really don't understand what diffrient frompublic class AClass {}
View Replies View RelatedI have a class for employees. This class has basic information for the employee but no real pay information. And 2 subclasses, one for employee's paid for hourly rates and one for those paid a yearly salary. Each subclass has their own pay() method, that calculates and returns their pay and extra fields relative to calculate that.
I'm just curious, if I do this and create an object for an hourly paid employee like so:
Object hourly1 = new HourlyEmployeeWilson("John Doe", "123 Tech Street",361961,"Human Resources", 0,12.50,50);
How can I utilize that classes public method of pay() to gather this instance (or hourly paid employee)'s pay? I've tried doing so via:
System.out.println(hourly1.pay());
But I get
DriverPayWilson.java:9: error: cannot find symbol
System.out.println(hourly1.pay());
^
symbol: method pay()
location: variable hourly1 of type Object
1 error
Which two method HashMap key object should implement?..
View Replies View RelatedI am working on an independent project it is a simple little text based rpg that will run in a counsel window. I have an object for Character that is creating during a CreateCharacter method. I want the play to be able to enter a character that will open up a menu that displays things like the name and health and stuff of the character from the object created in CreateCharacter, but because I have it in a different class I don't know how to reference the object made in CreateCharacter.
I have it in 6 files
Character --- Object with getters/setters for things like name, age, race, class, ect
MainMenu --- Displays title and promts for new game and quit
CreateCharacter --- Walks through and sets all values in Character
Stats --- Keeps the players stats (health, attack, ect) in an array
Intro --- Beginning demo thing (not really important for this question)
Menu --- Displays all current user stats (Having issues with this one)
Example I have this in Menu
System.out.println("Name: " + ????.getName());