One of my assignments was to make a program that would read a sequence of names and then list them all.Just to be clear, it would read them all first, and then it would list them all at the same time.
View RepliesI am trying to write a java program that asks the user for a list of names (one per line) until the user enters a blank line. At that point the program should print out the list of names entered, where each name is listed only once (i.e., uniquely) no matter how many times the user entered the name in the program. I am supposed to use an ArrayList for this problem.
My idea for a solution is to create an ArrayList<String>, read each name, i.e., line, entered and then to see if that name is already in the ArrayList. I created a for loop to check each element in the ArrayList but when I try to assign an element to a string variable I get the error "Type mismatch: cannot convert from Object to String". Not sure why that is happening because the ArrayList is defined as a String list.
Here is the code so far.
/*
* File: UniqueNames.java
*/
import acm.program.*;
import java.util.*;
[Code].....
I have a list of 100,000 + names and I need to append to that list another 100,000 names. Each name must be unique. Currently I iterate through the entire list to be sure the name does not exist. As you can imagine this is very slow. I am new to Java and I am maintaining a 15+ year old product. Is there a better way to check for an existing name?
View Replies View RelatedI'm trying to use the DataFactory class to pull in a list of names, as I need to populate my app in development with randomized test data for testing.
DataFactory
So, I can get a random name like so:-
package domainentities;
import java.util.Random;
import java.util.Collections;
import org.fluttercode.datafactory.AddressDataValues;
[Code] .....
But - it always prints 'Lindsey'. I need a way of completely randomizing but I can't see the class has a method to let me do this? I can use the randomize method but this takes an int argument which will always bring back the same index value (same name).
I wonder if I am over complicating this. I can use a simple String array of names, but I don't want, like 10,000 names in my array and I want a good way of generating good, randomized data. Perhaps a .csv file of names could be read in? Here is a second method I wrote but I don't have the skills to know how to read the array values from my large .csv file:
public String randomSecondName(){
String[] lastNames = {"Smith", "Jones", "Collins","Jackson",
"Dearsley", "Trump", "Carr", "O'Connell", "Dyer", "Furstzwangler" };
Random ran = new Random();
String lastName = lastNames[ran.nextInt(lastNames.length)];
return lastName;
}
An array which contain a list of names. I let for a user input and I use that to search through the array. For example lets say the string name "Christian" is stored inside the names array and the user types in Chri, the program looks in the array and finds a name that contains Chri and prints them out. How do I go about doing this?
View Replies View Relateda project I am working on. Its a program that creates a singly linked list that stores names and high scores and prints them. For some reason it is printing an entry extra times. Also my remove function is not working properly
GameEntry class:
package project;
public class GameEntry implements Comparable<GameEntry> {
private String name;
private int score;
public GameEntry(String n, int s) {
name = n;
[Code]...
I first learned how to program with BYOB. In BYOB there were variables and lists. Variables worked the same as Java and lists were groups of variables. To create a list, I would give it a name. I could then add variables to this list as items throughout the program. Here's an example of what a list would look like:
[[List]]
item 1: Hello
item 2: world
I could then call upon item 1 or item 2 and delete them if needed. In Java, I want to have 3 lists of variables into which I put user input as variables. The code would look something like the following: (stuff with "//" at the end is detailing what I want to do, not actual working code)
import java.util.*;
public class Archives {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
[code]....
import java.io.*;
import java.util.ArrayList;
public class SpiltList
{
private class node
{
int number;
node next;
[code]....
I am using an ArrayList to make a list of nodes. I cannot seem to find documentation on how to call the nodes, just find how to get int and strings from a list.
In Java® identifiers, you are allowed letters and numbers (also _ $£¢€ etc, but you should avoid them in normal identifiers). So you cannot have spaces. You cannot write public class Hello World because the javac tool will see World as a separate identifier and not understand what it means and will fail to compile the code. You must write public class HelloWorld instead. And because the class is labelled public you must call the source file Hello World. java. Since you can't have two classes with the same [fully‑qualified] name, you cannot write two public classes in the same source file.
“What about names of source files?” somebody will ask. Well, some file systems will permit spaces in file names; ext4 will and I suspect so will NTFS. Can you write file names with spaces in? You would have to have a different name of the class inside the file, because you can't have spaces, and you therefore cannot make the class public, but maybe you can write a package‑private class with a different name.
On ext4, you have to write out the name of the file and the shell will interpret the space as meaning there are two different file, so you have to escape the space.
campbell@campbellsComputer:~/java$ gedit My First Class.java
// My First Class.java
class Foo
{
public static void main(String... args)
{
System.out.println("Hello, World!");
}
}
campbell@campbellsComputer:~/java$ javac My First Class.java
campbell@campbellsComputer:~/java$ java Foo
I need to make a program that keeps track of peoples names, allows you to add a note to each name and preferably would reorganize whatever you put in by date or by spelling. (I suppose the phonebook application in cell phones is a good match, a supermarket's list of foods and prices would work as well).
View Replies View RelatedThe class Overloading below asks for two names and prints three different greetings. Your task is to write the class methods missing from the class declaration. Methods print the greetings as shown in the example print.
Hint:The names and parameter types of the needed methods can be checked from the main method because all methods are called there. This exercise also does not require you to copy the source code below to the return field.
The method declarations will suffice.
Example output
Type in the first name: John
Type in the second name: Doe
**********
Hi!
**********
Hi, John
**********
Hi, John and Doe
**********
import java.util.Scanner;
public class Overloading {
public static void main(String[] args) {
String firstName, secondName;
[Code] ....
Recently I have missed a few weeks of my class due to family emergencies. Because of this I have missed very important lectures. My professor has assigned me the following assignment:
Prices Write a Java program that specifies three one-dimensional arrays names price, amount, and total. Each array should be capable of holding 10 elements. Using a loop, input values for the price and amount arrays. The entries in the total array should be the product of the corresponding values in the price and amount arrays. After all the data have been entered, display the following output:
Total Price Amount
==== ==== ======
Under each column heading display the appropriate value.
I know how to display everything using printf, how to create the actual arrays and define the array size, but I am confused on how and what loop to use and how to construct it. This is what I have managed to write up so far:
import java.util.Scanner; // Imports the Scanner class
import java.text.DecimalFormat; // Imports the DecimalFormat class
public class Prices
{
public static void main(String [] args)
{
double[] price = new double[10];
double[] amount = new double[10];
double[] total = new double[10];
// Create a new Scanner object
Scanner keyboard = new Scanner(System.in);
} //End of main method
} // End of public class
I want to read json file as follow;
{
"M": {
"row": [
{
"col1": "c00"
},
{
"col1": "c10",
"col2": "c11"
},
{
"col1": "c20",
"col2": "c21",
"col3": "c22"
}
]
}
}
Next to reading I need to assign to two dimensional array, but without giving "col1","col2","col3" a lot.
The array is for example, Array[3][] = {{"c00"},{"c10","c11"},{"c20","c21","c22"}};
I am trying to make a calculator using Java GUI. I've managed to make an ActionListener and add it to a button, but I've made an error in my code that I'm unsure of how to solve. Because of how I've written the code, only one number can be placed in the text field. For example, the an ActionListener for the three button on the calculator was added to the button, but no matter how many times the user presses the button, only one 3 will appear in the text field. The code is below:
import javax.swing.*;//import the packages needed for gui
import java.awt.*;
import java.awt.event.*;
public class Calculator {
public static void main(String[] args) {
JFrame window = new JFrame("Window");//makes a JFrame
window.setSize(300,350);
[code].....
As you can see, because the compiler forces the String variable to be final, so when the user presses the button, the code simply shows how a space character and three character would look like, because the String variable can't change. How do I write my code so that every time the user presses the button, a character is added to the text field?
I would like to make a database using HTML and Java. I already made something like this using swing. I am just looking for some pointers here. I just started looking into Java Play 2 and I have a feeling this is what I am looking for. JavaEE is very complicated and I have read that it is being phased out. What is your opinion on this?
I want to make a static HTML page and put it on my home network and treat one of my computers as the sever accessing mySQL.
I want a completely unique GUI with unique buttons, like I could make it a giraffe if I wanted to! (not going to, but a giraffe seemed like a pretty irregular shape) ....
View Replies View RelatedI have to make the connect 4 game be connect 3. Ive edited a code but I the math is over my head. These loop methods check the ways someone can win.
for (int j=0;j<7;j+=2)//need to change
{
if ((f[i][j+1] != " ")
&& (f[i][j+3] != " ")
&& (f[i][j+5] != " ")
&& (f[i][j+7] != " ")
&& ((f[i][j+1] == f[i][j+3])
&& (f[i][j+3] == f[i][j+5])
&& (f[i][j+5] == f[i][j+7])))
//end of loop
[code]....
i am trying to make a platform game in java and to do this im trying to make a scrolling bacground. i can get the background image to scroll. However, i cant get the image to scroll forever, here is the code.
GamePanel class ( the jpanel )
public class GamePanel extends JPanel implements ActionListener{
static ArrayList<BackGround> store = new ArrayList<BackGround>();
public GamePanel(){
setFocusable(true);
Timer time = new Timer(5,this);
time.start();
store.add(new BackGround(0,-200));
the problem i have is that i want the bacground to loop. however, once the first instance of the background is done scrolling it freezes and doesnt load anymore. here is the code for adding a new background to the list
if(store.get(a).getX() <= -950 ){
GamePanel.store.get(a).setX(-900);
GamePanel.store.add(new BackGround(-951,-200));
}
How to build an array that calls methods if i understand it correctly .... if this is possible a simple example of this.
View Replies View Relatedso recently i made an applet and i was gonna put it up on my website when i got an error saying that java had blocked the applet duo to security thingys..sooo i looked in to it and i found out that apparently you need permission from java to run a applet or something like that, because there was a lot of viruses coming from there or something...
so does that mean only big game company's that can actually get permission by java make applets? are applets dead!? is there no other way to play java games in a browser!??!
i want to make a circle with java coding.... i tried but i am grtting some error...
View Replies View RelatedAny tips on how i can improve this simple resource calculator for this game called Clan of Clans.
It might even look more functional than OOP.
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class ClashOfClan {
private static String[] units = {"Barbarians ", "Archers ",
"Giants ", "Goblins ", "Wall Breakers ", "Balloons ",
[Code] .....
Suppose I have a class child
public class child{
public static int age = 1;
}
And I am using class child static variable age in class school
public class school{
int var_age;
public school(){ //school constructor
var_age = child.age;
}
}
Value in age of child class could be any of these below depending on some logic:
public static int age = 1;
public static int age = 2;
How could i achieve this where should i apply that logic? Also it is mandatory for class school code to remain same.
I need to make an java app which will be used only for online banking transaction with credit/debit card ...so i need to know the basic procedures for costumer to come and do the transaction
View Replies View RelatedI want to create simple java application which has 3 text fields and the application will have database connection. Once done, I want to run this application on other systems without using any IDE. So how do I do this? How can I make an application installable on other system so that on clicking on it, it will start executing?
View Replies View RelatedI am trying to make a java Simon game but I cannot figure out how to make the GUI work. I have this so far, but now it just keeps saying I lose and it isn't functioning. It seems the only way I can make it work is having the action listeners in the do loop, but then once a button is clicked, the code errors out.
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
[code]....