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;
}
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?
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.
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?
I 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.
a 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;
In my project I had to create 2 classes, Room and Animal.
Room had to have an array (NOT arrayList-I know theyre better and easier but I need to use an array, for now) This array must be able to be populated by 10 "Animals", and the Room class needs two methods, a method to add animal a to the room (rooms array) and a toString() that returns the name of the room and the names of the animals in the room. The teacher added a hint saying that this toString() should reference the animal classes toString()
Here is my code thus far:
public class Room { private String name; Animal[] inRoom = new Animal[10]; public Room(String roomName){ name = roomName; } public void addAnimal(Animal a){ for(int i = 0; i < 10; i++){
In a spreadsheet, alphabetical letters are column names and numbers represent rows. I have named the columns and I need to name the rows in the same way. Or if I am to set the first column in every row as row headers, how can I make then non-editable by the user? In addition to that, how can I make the table appear bigger? There's a lot of space but the table appears to be small.
I have some class called sorted to sort the linked list through the nodes of the list. and other class to test this ability, i made object of the sort class called "list1" and insert the values to the linked list.
If i make other object called "list2" and want to merge those two lists by using method merge in sort class. And wrote code of
list1.merge(list2);
How can the merge method in sort class know the values of list1 that called it as this object is created in other class.
Program is running fine. I can create usernames and everything but somehow I cannot quit or exit the program when I enter my sentinal value "QUIT". Here is my program question: Create an application that will create a username for a school computer system. Input a user’s first and last name. The username will be the first letter of the first name followed by the first 5 letters of his last name followed by a random 3 digit number. Continue to create and display usernames until a sentinel value is entered.
import java.text.*; import java.util.Random; import java.text.DecimalFormat; public class username
I'm using MS Access database. What I want to do, is to get all names of my tables in database.My SQL query :
SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES
is it correct? I found it in one example and didn't change anything.
I could of course execute this and check, but the problem is, that it returns ResultSet(I'm using Java), and I do not know how to manipulate this object in this situation.Cause usually ResultSet contains columns and rows, I think now I should get only bunch of String values.
i have this problem with my code. it need to put three names in alphabetical order that are entered from the user. then output the alphabetical result. the program compiles but when you put in different names there are not alphabeticals. i think only the first if works good.
import javax.swing.JOptionPane; public class Sort { public static void main(String[] args) { String name1; String name2; String name3;
I receive a java.lang.NumberFormatException: For input string: ""DepDelayMinutes"" error when trying to filter a list and then assign the results to a new list.
I have edited the code so it is an int that throws the exception so it isn't the presence of a string that is causing the error - java.lang.NumberFormatException: For input string: ""0914"" .
I believe the issue is because of the two sets of double quotes but I do not understand how they came about. The original dataset does not have any quotes whatsoever.
I have a JTable with the model " Names " , " Quantity " and " Unit " .
I'm coding a program where you get the ingredients names.
So i need to get the whole row of one column and String it all up together,because i need to store it in mySql and i have already set it all as String.
how i can do this ?
My code are as follows :
JTable Code:
DefaultTableModel model = (DefaultTableModel)table.getModel(); if(!txtQty.getText().trim().equals("")){ model.addRow(new Object[]{ingCB.getSelectedItem().toString(),txtQty.getText(),unitCB.getSelectedItem().toString()}); }else{ JOptionPane.showMessageDialog(null,"*Quantity field left blank"); }
Getting the values and for storing :
for(int i = 1; i<= i ; i++){ ingredients = table.getName(); }
This is for loop is wrong and it does not work because i have a constructor to take in Ingredients but because it is inside the loop, it cannot take it in.
I'm new to Methods and do not really know how to write a method header. What would an appropriate header look like for the following instance? getFilename: This method takes no parameters. It asks the user for a filename. If that file exists, it returns the filename. If it does not exist, it asks the user for another filename. It continues to ask for filenames until the user gives the name of a file that exists.
Also, how would I make a return tag for this and call it into the main method.
I give my dataset in csv (or text) format to my program but it says "(The system cannot find the file specified)" even though the file exists.
what should I do?
here is my code:
Java Code: public class ReadCSV { HashMap<String, Integer> authorList = new HashMap<>(); File file = new File("d:/Course/thesis/predict/whole.scv"); int authorCounter = 0; public static void main(String[] args) { ReadCSV obj = new ReadCSV();
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'm new to Methods and do not really know how to write a method header. What would an appropriate header look like for the following instance? getFilename: This method takes no parameters. It asks the user for a filename. If that file exists, it returns the filename. If it does not exist, it asks the user for another filename. It continues to ask for filenames until the user gives the name of a file that exists.
Also, how would I make a return tag for this and call it into the main method.
Write a program that asks the user for the names of two files. The first file should be opened for reading and the second file should be opened for writing. Ihe program should read the contents of the first file, change all characters to uppercase, and store the results in the second file. The second file will be a copy of the first file, except that all the characters w ill be uppercase. Use Notepad or another text editor to create a simple file that can be used to test the program
Here is my code. I Also made two text document files that are located in the same directory as the .class file (the code file) that are named OriginalFile and UpperCase respectively. Please let me know what I need to do. Here is the code.
import java.util.Scanner; import java.io.FileReader; import java.io.IOException; import java.io.PrintWriter; public class UpperCaseFile { public static void main (String [] args) throws IOException {
I found out what my next java class project is, and i am trying to get a head start on it. It is a simple address book. it needs to have 4 choices that get cycled through until quit is chosen:
1. add business contact 2. add personal contact 3. display contacts 4. quit
I have made an abstract contact class with a personal subclass and business subclass(all 3 are required). they have all been made, with set/get methods(the wonders of encapsulation and polymorphism have finally hit home!). The main program needs to add a new subclass object when chosen, and it needs to accept and store contacts by type
So, i am figuring 2 object arraylists for business/personal.
My question is: how do you create an object without having a name for it already programmed? Does it even need to have a unique name, since it would be stored in a seperate index and/or arraylist?
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).
I'm making a program that will read the file and put the numbers in a list of int arrays and names in another list of strings. In my program i created two classes. One will receive the numbers and the other will receive the names. But i only can read the numbers! How can I read everything and separate into two different lists?
try( BufferedReader br = new BufferedReader( new FileReader( jFileChooser1.getSelectedFile().getAbsolutePath() ) ) ) { hist = new Historic();//Will recieve the array of numbers. while( br.ready() ) { int line[] = new int[ 7 ];
I want to reverse grades that i have put using JOptionPane from largest to smallest and the corresponding names..
import javax.swing.*; import java.util.Arrays; public class ArrayUtils { public static void main (String[]args){ String length = JOptionPane.showInputDialog("Number of students");
