Radius Value Becoming Zero In Constructor
Jul 8, 2015
I am trying to create a user defined Exception. I am using a hard-coded value in the constructor of circle class at the time of object creation.But in the constructor this value becomes 0.
import java.lang.Exception;
import javax.swing.*;
class InvalidRadiusException extends Exception{
private double r;
public InvalidRadiusException(double radius){
r = radius;
[Code] ....
Due to this its always generating InvalidRadiusException even if i am supplying a non-zero non-negative value.
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May 31, 2014
This is the code
public class PondRadius {
public static void main (string[] args) {
//Calculate the radius of a pond
//which can hold 20 fish averaging 10 inches long
int fishCount = 20;//number of fish in pond
int fishLength = 10;// Average fish length
int inchesPerFoot = 12;//number of inches in one foot
[Code] ....
And here is the error or exceptions i received
C:javaLesson1>javac PondRadius.java
PondRadius.java:23: error: ')' expected
System.out.println("To hold" + fishCount + fish averaging " + fishLength +" inch
es long you need a pond with an area of
" +
[Code] .....
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Oct 24, 2014
I have to print points on a circle in increments of -0.1, but when I use a number larger than 1.3, the list stops at 0.1 larger than negRadius, and I don't know why. (Assume the center is (0,0))
public class PointsOnACircleV1
{
public static void main(String[] args)
{
double radius = 1;
[code]...
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May 1, 2015
Write a program that draws 20 circles, with the radius and location of each circle determined at random...... Two circles overlap if the distance between their center points is less than the sum of their radii...
There may be many problems with the code in general but what I'm struggling with is the distance and the totalradius portion. Visually, its inaccurate.
import java.awt.*;
import javax.swing.*;
public class CircleTest extends JPanel {
Circle []circles;
Circle []circleCenter;
Circle []all;
private int distance, totalradius, dx, dy;
private int radius,x,y;
[Code] ....
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Oct 8, 2014
I am supposed to write a Tester to get the current volume of a balloon that starts with a radius of 0 after it is inflated.This is the balloon:
public class Balloon
{
private double savedRadius;//instance variable
/**constructor!!
Constructs a balloon with a radius
*/
}
[code]....
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Mar 5, 2014
I am doing an assignment that is asking for the user to put in the radius of a circle and the program figures out the area, diameter and circumference. It is using 2 different java programs to accomplish this. One with the info on how to get area, diameter and circumference and one is the demo that runs the program. I keep getting errors on my demo.
// Circle Class
public class Circle {
private double rad;
private double Pie;
private double area;
private double diameter;
[Code] .....
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Jan 29, 2015
How do you use power of math. I'm trying to write a calculator to calculate the volume of a cylinder by asking the user to enter the height and radius but when I use pow(2) it doesn't work. I imported java.lang.math class so i dont have to keep using math. for now my code runs just fine since I'm using radius * radius but I would really luv to use the power instead times each other when i have to use higher powers.
import java.util.Scanner;
import static java.lang.Math.*;
public class Lab2 {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
[Code] .....
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May 29, 2014
(Corner point coordinates) Suppose a pentagon is centered at (0, 0) with one point at the 0 o’clock position. Write a program that prompts the user to enter the radius of the bounding circle of a pentagon and displays the coordinates of the five corner points on the pentagon. Here is a sample run:
Enter the radius of the bounding circle: 100
The coordinates of five points on the pentagon are
(95.1057, 30.9017)
(0.000132679, 100)
(-95.1056, 30.9019)
(-58.7788, -80.9015)
(58.7782, -80.902)
What we know , we know both the radius of the circle(user inputted) and the side of the pentagon from formula (double side = 2 * radius * Math.sin(Math.PI/5)) .We also know that one point is (0 .100) Also i know that the distance between 2 points is Math.sqrt(Math.pow(x1 - x2 ,2) - Math.pow(y1 -y2 ,2)) .
There might be other ways to solve it but this is my best bet trough i dont remember how to solve linear equations of the form x^2 + y^2 = - radius and radius ^2 = x^2 + (y - 100) ^ 2..
The solution i found is using the radius from the center to the point we want to find out and using the radius to the point we already know ( 0 .100) but i have to solve that damn equation first ...
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Apr 19, 2014
I was practicing my java skills and came across an exercise in which a non parameter constructor calls a two parameter constructor. I tried a few searches online but they all came back unsuccessful. This is the part I am working on:
public PairOfDice(int val1, int val2) {
// Constructor. Creates a pair of dice that
// are initially showing the values val1 and val2.
die1 = val1; // Assign specified values
die2 = val2; // to the instance variables.
}
public PairOfDice() {
// Constructor that calls two parameter constructor
}
I tried calling the two constructor using the line "this(val1, val2)" but I get an error because val1 and val2 are local variables.
Then I tried to use the same signature: "this(int val1, int val2)" but that didn't work either.
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Apr 23, 2015
I'm wonder about the issue of constructor for arrays. Let say I have a class tablica, and one component int[] tab. If I get it right until now tab is nothing more than empty reference to some unexisting array?
import java.util.Random;
class tablica{
int[] tab;
tablica (){ // i wish it was constructor
[code]....
Then, I'm trying to build the constructor for class tablica. What can be the parameter of such constructor? Is it fields of array? It is simple forf for basic variable
- I liken values defined in constructor with those global defined in class. But how to do it with array component tab.
If I create array object in main method then how can I use this constructor?
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Jan 31, 2015
public class TestClass {
public TestClass(String k){System.out.println(k);}
public static void main(String[] args) {
try {
hello();
}
catch(Exception e){System.out.println(e);}
[Code] ....
Explain how to catch block act as constructor with parameter?
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Aug 10, 2014
Java Code:
package ZooZ;
import java.util.Random;
public class Animal {
int playerOne; <------- Remains 0
int playerTwo; <------- Remains 0
Random random = new Random();
[Code] ....
If you look at the code, I set "playerOne" and "playerTwo", to set them as what was passed in from another class..
In the Animal constructor.
in that constructor the value is 2. But when I use it in the "Bash()" method it is 0 in the console.
Why doesnt the playerOne and playerTwo stay the value it is assigned in the constructor.??
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Oct 27, 2014
"A constructor cannot be abstract, static, final, native, or synchronized."
I understand on why it can't be all of the above, except "final".
Why can't we have a final constructor, i understand constructors are not inherited, hence no chance/case of overriding etc. But why is it not allowed at all ?
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Oct 27, 2014
So I am working on a school project and I have 2 classes, class FakeGravity contains all the properites and class BouncyBall is my driver class. For some reason when I try writing
FakeGravity gravity = new FakeGravity( );
I get an error. I am attaching an image of the error, and also attaching the program just in case you need more information. Also I was using blueJ to write the program
dcasarrubias, on 27 October 2014 - 02:44 PM, said:
So I am working on a school project and I have 2 classes, class FakeGravity contains all the properites and class BouncyBall is my driver class. For some reason when I try writing
FakeGravity gravity = new FakeGravity( );
I get an error. I am attaching an image of the error, and also attaching the program just in case you need more information.
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Nov 2, 2014
The LocalStudent class inherits the Student class. The IDE states an error of "no default constructor in Student class".I understand that if a LocalStudent object is created, the default constructor of its superclass (aka Student class) will be called implicitly.there is no LocalStudent object being created, so why is the default constructor of Student being called ?
The default constructor of LocalStudent is also overloaded by the created no-arg constructor containining subjects = null; . So there is no call to the superclass default constructor from the default constructor of LocalStudent.
public class Student {
private char year1;
public Student(String name, char year){
year1 = year;
}
public char getYear(){
return year1;
[code]...
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Nov 17, 2014
I want to add validation to some of the elements in my constructor.
Person(String idIn, String nameIn, ) {
this.id = idIn;
this.name = nameIn;
}
I want to be able to check that the data for the ID is limited to a certain collection of characters formatted in a certain. For example, I may wish to limit it to 5 lowercase letters or numbers, or a combination of both. How could I do this?
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Jun 23, 2014
Do we have constructor in abstract class? If we have then what is the use of it?
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Oct 21, 2014
For some reason, even though I am giving it the correct number of arguments for the constructor to be initalized it doesn't go through. I end up with a compile error:
PatientBuilder.java:17: error:
constructor Patient in class Patient cannot be applied to given types;
Patient aPatient = new Patient(bloodType, rhFactor, ID, age);
^
required: no arguments
found: String,String,int,int
reason: actual and formal argument lists differ in length
And I'm not understanding how that's possible when it calls for 2 strings and 2 ints and that's what I am passing.
I have this in my main method Scanner inputDevice = new Scanner(System.in);
System.out.println("What is the patients ID number?");
int ID = inputDevice.nextInt();
System.out.println("What is the patients age?");
int age = inputDevice.nextInt();
[Code] ....
And then here are my two constructors, one default and one overloaded.
public Patient() {
patientBlood = new BloodData();
ID = 0;
age = 0;
bloodType = "O";
rhFactor = "+";
[Code] .....
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Mar 19, 2014
How to use a constructor with parameters where the user inputs the information? I'm doing a problem where I create a Delivery class that accepts arguments for the year, delivery number within the year, distance code (1 for short distance, 2 for long), and weight of package. The constructor is supposed to also determine the eight digit delivery number (combining the year and delivery number, like 20140054 for this year, package #54).
I know I'm not close to being done but I'm struck on the application with the constructor parameters. If I'm asking the user to input the information, does that mean I have to create a no argument constructor so it will compile? Right now it won't compile because it's asking for the parameters but I can't put them.
This is the class:
public class Delivery {
int year;
int delNum;
double weight;
int code;
[Code] .....
And the error is:
CreateDelivery.java:22: error: constructor Delivery in class Delivery cannot be applied to given types;
Delivery firstDelivery = new Delivery();
^
required: int,int,int,double
found: no arguments
reason: actual and formal argument lists differ in length
1 error
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Sep 1, 2014
I'm having an issue returning data from a constructor. This is an assignment, and the specifications were that two classes are to be used, one for the variables and assigning methods, and one for the main method and the printing. This app compiles, but returns "0" for the isbn number, and I'm sure it's because I'm not doing something right with my constructors. My code is below
public class Book {
/* Declare Variables */
public static int isbn;
/* Constructor */
public Book (int isbn) {
isbn = 454545;
[code]....
There are other variables to add, but if I can get one working, I can get the rest working.
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Jun 13, 2014
I did this using ArrayList<String> and my tests worked. Meaning I was able to read the strings in a different class through my constructor. However I want to use a string array because it will be easier to handle when I finish the program. I will send each players poker hand in and figure out who is the winner instead of putting it all onto a ArrayList and having to iterate through it. However whenever I did my check I am just printing null.
PokerFile class
void separateHands(String cards) {
//ArrayList<String>playerOne = new ArrayList<String>();
//ArrayList<String>playerTwo = new ArrayList<String>();
String[] playerOne = new String[10];
String[] playerTwo = new String[10];
[Code] .....
ignore the boolean methods I was just building the structure of the program. The print file is what is outputting this:
null
null
null
null
null
null
public class WinningHand extends PokerFile {
//ArrayList<String> p1 = new ArrayList<String>();
//ArrayList<String> p2 = new ArrayList<String>();
String[] p1 = new String[6];
String[] p2 = new String[6];
WinningHand(String[] p1,String[] p2)
[Code] ....
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Oct 2, 2014
what weapon the user wants to use and set the element of the Player but I can't use defineWeapon() inside of the constructor so what can I do?here's the player class (where I need to set the element which is the second string in the constructor
package netHackDessart;
import java.util.Scanner;
public class Player extends Monster {
public Player()
{
super("player", "null", 18, 6, 150, 4, 1, 6, 1, 8, 1, true, false);
[code]....
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Jan 8, 2014
What is the difference between two statements:
Class1 class1 = new Class();
class1 = Class2.method1();
and
Class1 class1 = Class2.method1();
I have one more query on the same lines ... I always need to call the method1 of Class2 whenever i create a object of class1. So I wanted to go with the constructor in Class1. But the method1 in Class2 has a return statement. so is there any better way to do this other than constructors.
Sample code:
public int class Class2{
public static method1(){
return 2;
}
}
public class Class1{
public Class1(){
Class2.method1();
}
}
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Nov 11, 2014
I am having an issue with a small part of my project. i am supposed to make a hash table with a file containing words. The file is being passed into my constructor, where i basically just all it "filename" of type string. Im supposed to get the contents of the file and put it into the table. the problem I'm having is making the connection between my constructor and a method called "start" which basically does all the work. Im not sure how to go by doing this, how could i use the variable "filename" from my constructer in my start method?:
import java.io.*;
import java.util.*;
public class WordCount {
//private fields, including your HashMap variable
HashMap<String,Object> hmap =new HashMap<String,Object>();//(table size,load factor)
public WordCount( String infileName){
String filename =infileName;
[Code] .....
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Jul 10, 2014
Constructors are public by default ,aren't they?
import java.awt.Frame;
import java.awt.SplashScreen;
import javax.swing.JOptionPane;
[Code]....
This code gives me error
The constructor SplashScreen(long) is not visible
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Nov 19, 2014
I am getting error in second constructor that I have created, it gives an error: cannot find symbol variable
package Objects;
import javax.swing.JOptionPane;
public class Constructor {
public static void main(String[] args) {
Piggybank1 pg1 = new Piggybank1("Abhinav", 500);
pg1.deposit(200);
pg1.withdraw(10);
[Code] ....
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