I need to add an employee object that my program has created and put it in a array list. My employee object is first name, last name, and a generated id. I am trying to add a new employee object to an array like this:
public static Employee addEmployees(String first,String last) //this method is in my employee class
{
Employee employee = new Employee(firstName,lastName);
employee.setFirstName(firstName);
employee.setLastName(lastName);
employee.getId();
employeefile.addEntry(employee); //add employee object to array list
[code]...
how to println it to test, but I can't seem to do that or know which class to put this function in. I know about for loops and such, just don't know how to implement it or where.
this is part of a larger project but i figure if i can figure out this first step i can work the rest. I need to get a title from the user add it to a object array (i think thats what it is) and then when i call listAllItems(), items[] should be copied into a string array called listAllItems, and then printed, but currently im jusst having trouble i think making it an object and then make it an item in the items[], if i run case 3 the list it says null...
public class MediaItem { String title; MediaItem(){ } MediaItem(String title){
I have been having trouble with a recent hw assignment requiring us to sort user defined data types in an array. so far, i have implemented the sorting algorithms correctly but i cant seem to store a string and an integer together. I have an employee class
[public class employee { private String Name; private int IdNumber; public employee(int IdNumber,String Name){ this.Name=Name; this.IdNumber=IdNumber;}
[Code] .....
And in my app, i create a employee object-----> employee john=new employee(1020, "John");
How can I prompt my insert method to take in employee id and string name together?
package com.practice; public class Car { private String name; //name of the car private String modelName; //Name of the model private int year; //The year car was made in private int speed=0;
[Code] ...
It wont let me copy it into a array is there any solution to this.
I need to return all the object name of one class in an array. I have a class named country, and other classes with athletes and medals etc. I need to do a method that list an array with all the countries that participate, so all the objects created with the class country (i.e canada.country, usa.country, etc). Is there a way I can retrieve them?
I need to return all the object name of one class in an array. I have a class named country, and other classes with athletes and medals etc. I need to do a method that list an array with all the countries that participate, so all the objects created with the class country (i.e canada.country, usa.country, etc). Is there a way I can retrieve them?
I need to be able to call this method and it should take the object and, add it to my list of items, but I am having trouble getting it to work. I know the numbers and stuff aren't correct eventually it will add one to the array length when i call add item, but I am just trying to go one step at a time
//creates new MediaItem object and add it to items[] void addNewItem(String title){ MediaItem object = new MediaItem(title); MediaItem[] items = new MediaItem[1]; items[0] = ("object.getTitle()"); numberOfItems = numberOfItems + 1; System.out.println(items[0]);
I am trying to build a method that takes an array of object and adds a new object of that type to the end of it . ONLY ALLOWED TO USE ARRAY , NO ARRAYLISTS VECTORS ECT . i realize that if the array is full you can use the java copy array method to make a new array and double its size until a certain point . The MAX AMOUNT OF OBJECTS is a constant that is 100 but for some reason even when executing my code i keep getting null pointer exceptions or index out of bounds errors , i have written this method many times now with out any success.
My question is how do I write a method that adds an object to the end of an array and if there are no spots left copies the current array into a new array and extend the size
private Animal [] objects; final int MAX_ANIMALS = 100; public AnimalObject() { objects = new AnimalObject[MAX_ANIMALS]; } public AnimalObject(Animal[]a)
Suppose that you have an ArrayList and that it contains String objects. Which declaration of the ArrayList requires that objects retrieved using the get method be cast to Strings before calling a String method?
I. ArrayList a = new ArrayList(); II. ArrayList<Object> a = new ArrayList<Object>; III. ArrayList<String> a = new ArrayList<String>;
A. I only B. II only C. III only D. I and II only E. I, II, and III
I know that all of these are ways to declare an Array List, but I am unfamiliar with the last two since I usually just declare my Array Lists with the first option.
I am trying to solve involves an object array each object has two instance variables, a string(origin) and a double(price), that was originally unsorted I have already sorted the array. There are a total of 11 possible origins and 6 prices, so obviously some origins share prices with others. The array is sorted by origin alphabetically ignoring case. I now have to write to a file how many instances of each origin there is, tally up all the prices for each origin and a total for all prices. I get bonus points for utilizing the presorted array to my advantage for the final output and calculations.
It would be easy to write a branching statement and tally up all the origins and prices etc... However this is a linear operation and doesn't seem to benefit from the presorted array at all so I came up with what I think is a descent alternate solution.
I was thinking that I could go through the array one object at a time and stop when I came to an origin of the next type. For example: there are 12 names called "Adam" and then a name called "Bob". So if I stop at bob, check the index and add 1 then I know how many Adams there were. I can then continue this process with all the other names, all the while calculating the combined prices and all.
I am trying to create an array filled with the object Card. It keep throwing the exception that the "deck is empty". I am not sure why that's happening because the code for filling the array seems fine.
public class Deck { private Card[] deck; private CardPile cardPile; private int numCards; public Deck() throws InvalidDataException{ this.deck = new Card[52];
Write a program that prompts the user for information about some countries, creates an object for each country, and then stores the objects in an array. After the user has entered information about all the countries, your program should print out which countries in the list have the smallest and largest area and population density. Assume the user will enter information about at least one country but that the program will not have to store more than ten countries in the array. The user will indicate that they are done entering countries by typing "DONE" for a country name. Here is an example of what your program must look like when it is executed (user input is shown bold)
Please enter the name of a country: United States Enter the area in square km and population of United States: 9827000 310000000 Please enter the name of a country: Mexico Enter the area in square km and population of Mexico: 1973000 122300000 Please enter the name of a country: Canada Enter the area in square km and population of Canada: 9985000 35160000 Please enter the name of a country: Liberia Enter the area in square km and population of Liberia: 111370 4294000 Please enter the name of a country: DONE
Liberia has the smallest area at 111370 square km. Canada has the largest area at 9985000 square km. Canada has the smallest population density at 3.521282 people per square km. Mexico has the largest population density at 61.986822 people per square km.
I don't know, I'm really confused with this Java program. I don't know how to do the main part of the program where the user inputs, array, and the output.
// Access the Scanner and ArrayList class by importing the java.util package. import java.util.Scanner;
/** Project - A Country Object * The purpose of this program is for the user to enter some information at most 10 countries. After the user has entered information about all the countries, the program should print out which countries in the list have the smallest and largest area and population density. */
public class Country { private String countryName; private int theArea; private int thePopulation; public Country(String countryName, int thePopulation, int theArea)
I'm working on a method that would parse the value of the array of object that I passed through a parameter. I would like to ask if making Object as a parameter is doable. Let's say I have a class Student and Teacher. I created a class the would handle the sched and name it class Schedule and extend this class to the Student and Teacher. Now I want to have a function that will accept an array of Schedule from either Student and Teacher, what ever object I will pass in the parameter. I know its easy to just make a method with a separate parameter of my classes but im looking for a more dynamic code.
class Student extends Schedule{ //variables here for student } [code]
class Teacher extends Schedule{ //variables here for teacher } [/code]
private void parseObject(ArrayList<Object> objct){ Schedule temp = objct.get(0); //there is no error in this part
}
Now when i will try to use the function and pass a data, it will not accept since my parameter should be an array of object. How would I twist dis one?
ArrayList<Student> temp_student = new Array.... parseObject(temp_student); // it will not accept my parameter, how would i make it as an object
So I want to write a constructor that creates a new object with the data from the array values. I don't know where to start. It's the last method in the code:
public class Measurements { private double[] values; private double[] newArray; private int n; //numberofvalues private double[] ms; public Measurements(int max) { //constructor
This is what I have to create : Write a method that returns the largest object in an array of objects. The method signature is:
public static Object max(java.lang.Comparable[] a)
All the objects are instances of the java.lang.Comparable interface. The order of the objects in the array is determined using the compareTo method.
Write a test program in the main method that creates an array of ten Strings, an array of ten Integers, and an array of ten java.util.Dates, and finds the largest string (i.e. in the alphabetical order), Integer, and Date in the arrays.
Name your java class Max and your java file Max.java.
I am struggling a bit with this code as I am sure you can see, and am at loss. I have never used the compareTo method. Am I doing this right, or on the right track with my code?
public class Max implements Comparable { public static Object max(java.lang.Comparable[] a) { java.lang.Comparable tempObj = null; for (int i = 0; i < a.length; i++) { if (a[i].compareTo(tempObj) > 0)
I'm trying to make an array of objects, which I then initialize using objects that I have already created. I have main class, a secondary "Other" class, and a third "Other2" class. In the first Other class, I create three objects of the Other2 class, an object array of the type Other2 , and I then try to add the three objects to the object array, which results in the errors:cannot find symbol: class objectArray, ] expected, identifier expected
here is my code:
Other class public class Other { Other2 object1 = new Other2(); Other2 object2 = new Other2(); Other2 object3 = new Other2();
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 working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code] .....
And then here is the data from the text file that i must extract to use to create product objects.
These continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quantity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data. Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity;
[Code]...
these continue for about 40-50 entries, they are not seperated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name seperated with spaces, then price after a comma, then quanity after the second comma.....
I am working on a project that requires me to build a database with random access file, representing products, the base product contains a name (about 30 characters), a price (double), and a quantity (integer). I have worked on this project for probably 15+ hours and have tried so many things and feel like I've barley made any progress...
The part i am really struggling with is taking the data from the text file and creating an object array with it using the product class. Once ive accomplished that, i have to use that data to create a random access file with the data.
Here is the base Product class that must be used to create the objects for the array.
public class Product { public String pName; public String stringName; public double price; public int quanity; //Constructor public Product( String pName, double price, int quanity )
[code]....
and then here is the data from the text file that i must extract to use to create product objects.
Dill Seed,938,34
Mustard Seed,100,64
Coriander Powder,924,18
Turmeric,836,80
Cinnamon (Ground Korintje),951,10
Cinnamon (Ground) Xtra Hi Oil (2x),614,31
Cinnamon (Ground) High Oil (1X),682,19
these continue for about 40-50 entries, they are not separated by a blank line though i had to add those so it would display correctly, each entry is on its own line with name separated with spaces, then price after a comma, then quanity after the second comma.....
I am new to Java and have read books, the Java docs, and searched the Internet for my problem to no avail. I have an Array of objects that contains strings. How can I get the object's strings to print in a list so that the user can select that object to manipulate its attributes? For example, the user can select "Guitar 1" from a list and manipulate its attributes like tuning it, playing it, etc. I have a class called Instruments and created 10 guitar objects.Here is the code:
Instrument [] guitar = new Instrument[10]; for (int i = 0; i < 10; i++) { guitar[0] = new Instrument("Guitar 1"); guitar[1] = new Instrument("Guitar 2"); guitar[2] = new Instrument("Guitar 3"); guitar[3] = new Instrument("Guitar 4"); guitar[4] = new Instrument("Guitar 5"); guitar[5] = new Instrument("Guitar 6");
Now lets say that I want to access a method 'addInterest()' that is in the 'SavingsAccount' class I would have to do: '((SavingsAccount)s).addInterest();'
The question I have is why do I have to cast 'b' to SavingsAccount? Isn't the actual object reference of 'b' already an instance of 'SavingsAccount' class? How does the 'BankAccount' affect the object itself? I'm really confused as to what class is truly getting instantiated and how BankAccount and SavingsAccount are both functioning to make the object 'b'.
