Creating Methods Using Arrays - Fraction Class
Sep 27, 2014
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?
View Replies
ADVERTISEMENT
Apr 25, 2014
We're learning how to use Binary I/O commands...which equates to....
My issue is trying to relate the Fraction objects (which we are to create using a loop) with the read/write methods used in Binary I/O (input/output streams). I left a blank after the output.write(), so you can see where the issue exist.
Java Code:
import java.io.*;
public class FractionTest {
public static void main(String[] args) {
int [] fraction = new int[3];
for(int i = 0; i <= fraction.length; i++){
Fraction numbers = new Fraction();
[Code] ....
View Replies
View Related
May 5, 2014
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] .....
View Replies
View Related
Feb 15, 2014
I've been writing a fraction class code below that does a number of arithmetic calcs and when I run it these are the results I get. My gcd doesn't work when it comes to negative fractions and I'm not quite sure how to print.out the boolean methods ((greaterthan)), ((equals))and ((negative)). I'm also not sure if I have implemented those 3 methods properly. I'm still learning how to do unit testing.
Enter numerator; then denominator.
-5
10
-5/10
Enter numerator; then denominator.
3
9
1/3
Sum:
-5/30
-0.16666666666666666
Product:
-5/30
-0.16666666666666666
Devide:
-15/30
-0.5
subtract:
-45/90
-0.5
negative:
1/6
0.16666666666666666
Lessthan:
1/6
0.16666666666666666
greaterthan:
1/6
0.16666666666666666
FRACTION CLASS
import java.util.Scanner;
public class Fraction
{
private int numerator; //numerator
private int denominator; //denominator
[Code] ....
View Replies
View Related
Aug 22, 2014
I'm working on a side project, which will eventually hopefully be a Pokedex, and I've just been going to it at the end of every chapter and using the stuff I've learned to work on it.So I just read chapter 3, which is all about variables and teaches how to use arrays.
my question is, does an array have to be declared inside a method? Because I'm trying to create an array inside a class without any methods and without the main, and I continuously get errors. Here's a quick working of my code that won't compile.
class blah {
blah a[] = new blah[7];
a[0] = new blah();
}
The error message focuses on a[0] = new blah(); Telling me the 0 should be a ], the = is an illegal start of type, so on and so forth. The program compiles completely fine if it's within a method, like this:
class blah {
void a() {
blah a[] = new blah[7];
a[0] = new blah();
}
}
Or if I have public static void main (String[]args); But I'm trying to practice working outside of main.So does an array have to be within a method,
View Replies
View Related
Jan 4, 2015
I am receiving one error when using arrays and methods. It's at the bottom of the code and I have commented what the error is .
import java.io.*;
import javax.swing.*;
public class CEO_PROGRAM_PartB
{
public static void main (String[] args) throws IOException
[code]....
View Replies
View Related
Oct 9, 2014
So in my java class we are suppose to ask for how many names are going to be entered, create an array of that length, and then store that many inputted names. We then take those names, alphabetize them, and create a set of pairs. For example, it might look like this:
How many people are there? 4
Please enter the names of those people:
Dana
Bob
Alice
Charlie
There are 6 possible pairings. They are:
Alice & Bob
Alice & Charlie
Alice & Dana
Bob & Charlie
Bob & Dana
Charlie & Dana
We are also suppose to account for less than two names (both 1 and 0 as well as negatives).
I keep getting a null point exception error and I can't figure out why. Even debugging in Eclipse doesn't give any pointers except that it is originating in line 76.
import java.util.Scanner;
import java.util.Arrays;
class partners
{
public static int numNames;
public static int numPairs;
[Code] .....
View Replies
View Related
Apr 15, 2014
I'm trying to read user input from the terminal and separate the input into separate arrays depending on if the user input is an integer, scanner, or a string. The terminal should keep asking the user for input until the user types "quit".
import java.util.*;
public class arrayScanner {
public static void main(String[] args) {
ArrayList<Integer> intList = new ArrayList<Integer>();
ArrayList<Double> doubleList = new ArrayList<Double>();
ArrayList<String> otherList = new ArrayList<String>();
[code].....
View Replies
View Related
Mar 31, 2014
I'm having a problem printing out the descending order of my array. The array order goes like (Title,Studio,Year). I try to create to ints with the compareTo method but when the program is run the I get array out of bounds. Could the answer possibly be that in order not not have the out of bounds error, to create a for loop inside of the while?
public class Movie2
{
// instance variables
private int year;
private String Title;
private String Studio;
[code]...
View Replies
View Related
Feb 14, 2015
I am trying to create a program that reads a sentence, such as: "abba is running to the radar" scans this sentence, and then prints out all the palindromes. I am running into issues with my arrays and for statements. Here is my code:
static String palindrome, backwardsLower,
palindromeLower, palindromeClean, backwards2, backwards = "";
static String[] words;
static int counter;
public static void main(String[] args) {
palindrome = JOptionPane.showInputDialog("Please enter a phrase. " +
[Code] ...
I am aware that there is a few "useless" variables in there at the moment, I will clean them up (as well as some useless statements, I see those too). The issue comes at about line 17. The variable backwards REMOVES all the spaces from the array, so when it comes time to compare the strings, it is comparing individual words to the ENTIRE string, thus no words will ever be a palindrome.
View Replies
View Related
Nov 13, 2014
I am designing a program that generates 3 random numbers from 1-5 and if 2 match, the user wins $1. If 3 match, the user wins respectively:
All 1s - $5
2s - $10
3s - $25
4s - $50
5s - $100
I first used a loop to run until the user runs out of money or wishes to stop. Then I made 2 methods. 1 to generate the random numbers and 1 to see if the user won any money. I am storing the random numbers in an array called slotnumber.
This is what I have so far but I am getting compiling errors at while (cont == 'y') {
import java.util.Scanner;
import java.util.Random;
public class SlotMachine
{
[Code]......
View Replies
View Related
Nov 19, 2014
Here are the errors I am getting:
SlotMachine.java:21: error: illegal start of expression
public static void getNums(int [] slots)
^
SlotMachine.java:21: error: illegal start of expression
public static void getNums(int [] slots)
[code]....
i keep fixing small things and cannot get it to compile. Below is the original code,
import java.util.Scanner;
import java.util.Random;
public class SlotMachine
{
public static void main (String args[]) {
int userMoney;
Scanner input = new Scanner(System.in);
System.out.print("How much money to start with?
[code]....
View Replies
View Related
Jul 23, 2014
My assignment is to essentially update a calculator program that uses strings, and methods, to include arrays. How to create and call an array that the user defines the size of and then inputs the numbers to fill the array. Here's the example my prof gave us of what the output should look like:
Menu
1. Add
2. Subtract
3. Multiply
4. Divide
5. Dot product
6. Generate random array
7. Quit
What would you like to do? 1
How many values are in the arrays? 3
Enter the values in the first array, separated by spaces:
2 4 6
Enter the values in the second array, separated by spaces:
1 3 5
The result is [3.0, 7.0, 11.0]
How to create an array that would allow the user to define the size of the array and then inputs the values for the array? I'm completely lost. I never should have taken java as an online class.
View Replies
View Related
Mar 5, 2015
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?
View Replies
View Related
Mar 20, 2014
public class demo
{
Public class static void main(String[]args) {
//Creating a variable that will be a reference to the object
Peoples person_one;
[Code] ....
I have assembled this code below that has a void method which will creat a new object. Problem I encounter is that in
Create_object(person_one);
the person_one has an error saying not initialized. I'm jus trying to learn on my own ways here and practice so may know what's wrong with this? I know I can use a return object from methods but what about this approach?
View Replies
View Related
Sep 14, 2014
I want to make a program where users are prompted to enter a username and a password and have these two values create a new instance of the Object User. But I'm not sure where to start.
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
createUser();
[Code] ....
how to take username + password and put it into an object.
View Replies
View Related
Jul 21, 2014
So I have this class containing all my Enum types, also including methods for fetching Enum types based on their title attribute:
abstract class Enums {
static private Landmass getLandmass(String name) {
for ( Landmass l : Landmass.values( ) ) {
if(l.title.equals(name)){
return l;
[Code] .....
The second method (getAttribute) is created by copy-paste and I also need to repeat this exercise with several other types of Enums. This seems like a waste of code however.
Instead, I thought I'd create a generic method for fetching any type of Enums. As far as I could follow the tutorial @ Oracle I need a generic class for this. Thus the EnumHelper class:
abstract class EnumHelper<T> {
private T getEnum(T type, String name) {
for ( type t : type.values( ) ) {
if(t.title.equals(name)){
return t;
}
}
return null;
}
}
This, however, doesn't compute:
horoscopeEnums.java:234: error: cannot find symbol
for ( type t : type.values( ) ) {
^
symbol: class type
location: class EnumHelper<T>
where T is a type-variable:
[Code] ....
2 errors
To be honest I haven't been able to make much sense of the documentation on generics, thus its no surprise I'm stuck.
View Replies
View Related
Jul 14, 2014
I thought you can only create a new object using private implementations and then using a constructor to set your arguments inside the parameters of the constructor to the instance variables but how come he created an object without any private implementations and just methods inside the constructor.
import javax.swing.JFrame;
public class MyWindow extends JFrame {
public static void main(String[]args){
new MyWindow();
}
public MyWindow(){
setSize(500,500);
setVisible(true);
setTitle("MyWindow");
}
}
View Replies
View Related
Oct 7, 2014
This is titled "Creating static methods that accepts arguments and returns a value". I think that I understood everything about this except for the very bottom part of the code. I wasn't really sure where to put it. From the errors that I am seeing, I know which line is giving the errors but I'm not sure what is wrong with it.
import java.util.Scanner;
public class ParadiseInfo2{
public static void main(String[] args){
double price;
double discount;
[Code] ....
Errors:G:ParadiseInfo2.java:29: error: illegal start of expression
public static double computeDiscountInfo(double pr, double dscnt)
^
G:ParadiseInfo2.java:29: error: illegal start of expression
public static double computeDiscountInfo(double pr, double dscnt)
[Code] ....
6 errors
Tool completed with exit code 1
View Replies
View Related
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?
View Replies
View Related
Jul 5, 2014
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]....
View Replies
View Related
Jun 10, 2014
Design a class named Person and its two subclasses named Student and Employee. Make Faculty and Staff subclasses of Employee. There is also a MyDate class as explained below. A person has a name, address, phone number, and email address. A student has a status (freshman, sophomore, junior, or senior). Define the status as an integer which can have the value 0 (for "Freshman"),
1 (for "Sophomore"),
2 (for "Junior"), and
3 (for "Senior"),
but don't allow the status to be set to any other values. An employee has an office, salary, and dateHired. The dateHired is a MyDate field, which contains the fields: year, month, and day. The MyDate class does not explicitly inherit from any class, and it should have a no-arg constructor that sets the year, month, and day to the current year, month, and day. The MyDate class should also have a three-argument constructor that gets three int arguments for the year, month and day to set the year, month and day.
A faculty member has office hours and a rank. Define the rank as a String (for values like "Professor" or "Instructor"). A staff member has a title, which is also a String. Use data types for the fields as specified, or where one is not specified, use a data type that is appropriate for the particular field. Write a test program called TestEveryone.java that creates a Person, Student, Employee, Faculty, and Staff object, and invoke their toString() method (you don't need to call the objects' toString() method explicitly).
Note: Your MyDate.java class is the object class that your dateHired field is created from in the Employee.java class.
Do not use the Person, Employee or Faculty classes defined on pages 383 and 384 of the book. Create new ones.Here is the code I have so far concerning the employee and MyDate.
public class Employee extends Person {
private String office;
private double salary;
//private MyDate dateHired;
//7 argument constructor for employee
public Employee(String name, String phoneNumber, String email, String address, String office, double salary /*MyDate dateHired*/) {
super(name, phoneNumber, email, address);
[code]....
View Replies
View Related
Feb 7, 2014
I've a parent class with a argument constructor like below(a sample code)
public class Parent {
Parent(String name) {
System.out.println(name);
}
public static void main(String[] args) {
}
}
Also I've child.class which extends Parent.class as shown below,
public class child extends Parent {
child(String name) {
super(name);
}
}
Now, I want create/modify the constructor which is in child, by taking "int i" as an input instead of "String name". How can I do that? Run time I want to execute child constructor not a parent constructor.
Condition is: Without making any changes to the Parent class
View Replies
View Related
May 20, 2015
In the process of creating a new class, I need to move my main method from the class SaveDate to the class DynamicTest. Below I have listed the code of both classes.The objective is to be able to run my program from the DynamicTest Class. I need understanding the process of moving my main method to a different class and creating an Object of a class and calling its method.
public class SaveData {
private static final Map<String, Object> myCachedTreeMap = new TreeMap<String, Object>();
public static final List<String> getLines(final String resourceParam, final Charset charset) throws IOException{
System.out.println("Please get: "+resourceParam);
if (myCachedTreeMap.containsKey(resourceParam) ) {
// Use the cached file, to prevent an additional read.
[Code] ......
View Replies
View Related
Jan 30, 2014
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..
View Replies
View Related
Nov 22, 2014
I have an Abstract Class called GameColorEffect which contains a number of non-static Inner Classes that extend their Parent Class, GameColorEffect. I want to be able to create instances of the Inner Classes, however my IDE, eclipse, prompts me with the error:
No enclosing instance of type GameColorEffect is accessible. Must qualify the allocation with an enclosing instance of type GameColorEffect
And eclipse shows me a possible solution which is to turn the Inner Classes to static, this would allow me to create instances, but not really. This is because using methods from the static Inner Classes that change values in the Inner Classes will do this for every instance of the same Inner Class which is literally like a single instance. However, I want these Inner Classes to be individual with their values and still be able to use them outside as instances. I've found out a possible solution, which I'm not sure works like I want it to:
Java Code : GameColorEffect = new GameColorEffect.ExampleEffect(); mh_sh_highlight_all('java');
However, this is in-compact because sometimes all I need is to use just a method like:
Java Code : new GameColorEffect.ExampleEffect(intensity).applyEffect() mh_sh_highlight_all('java');
And another solution that I already knew prior was that I could make the Inner Classes proper classes not inside of the GameColorEffect class, but this is also in-compact because I will have to have so many classes for the so many effects that I have.
View Replies
View Related
