ArrayList Index Check
Nov 12, 2014How could I check if an index is exist in an array list? I mean, I should enter an integer and it should return me a boolean result that saying whether if that entered value is an index or not.
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Identity Program - Check If Randomly Generated Number Match Index
Apr 14, 2015I have this program where I'm supposed to fill an array with 1000 indices with 1000 randomly generated numbers between 1 and 1000. The program is supposed to check if any of the numbers match an index that is the same value (so for example, the number 4 is in index 4). How to check for that condition, especially using a binary search (I'm also told to use a binary search).
Right now the variable index isn't initialized because I don't know what to initialize it to exactly. How do I check to see if any numbers match the value of the same index?
import java.util.*;
public class Identity {
public static void main(String[] args) {
int [] integers = new int [1000];
// Fill array with randomly generated numbers
int [] display = GenerateRandom(integers);
[Code] ....
All Of ArrayList Objects Have Been Given Index Of -1
Nov 15, 2014So I am working on an assignment and ran into an annoying bug. Basically i have a menu that accesses an ArrayList of Videos which may or may not be read from a file, one of the options of the menu is to edit an existing Video. For this I ask the user for the number of the video and it is checked against the list of video numbers if it returns a match, the method gets the index of the Video object and stores it in a temporary variable the user is allowed to edit the details and the object is put back into the ArrayList using the variable and the ArrayList's set() method
My problem is that once i finish editing the details of a video it gives me a indexOutOfBounds exception
On further investigation using a method that goes through the index of every object in the ArrayList using indexOf() i found out that every single object has been given the index of -1 and not 0,1,2,3 etc.. This is my first error and have not expierenced any other before.
The objects do exist because I have read them from a file. I can also add new Objects and view them successfully but they still have the same index . I have checked my syntax and everything and no errors, this happens at run time only.
I have even created some other ArrayLists seperately and debugged them and their index order is fine. I am too far into this project to start over. I've also tried cleaning the project(my IDE is Eclipse).
How To Check To See If A Character Is In Arraylist
Apr 15, 2015What I'm trying to do is say if the array contains the character a, then output: this letter is already in the array. I tried
if(arrayList.contains(a)) {
System.out.println("This is already in the array!");
}
but it's not working. What should I use?
ArrayList - How To Get Index Of Element
Feb 1, 2015I am just studying over ArrayLists and i have encountered a problem, i'm trying to get the index of an element but it keeps returning -1. Here's the code
Java Code:
import java.util.ArrayList;
public class PhoneEntry {
String name;
String phone;
public PhoneEntry(String name, String phone) {
[Code] ...
I know the list is not empty because it returns a size.
Setting Int And String To Index In ArrayList
Apr 27, 2015I would like to know how to set a int and a string to the same index in Array list. For example index 0 would have 5 and "Apple".
View Replies View RelatedHow To Check If ArrayList Of Object Contains A Certain String
Mar 25, 2015I have a number of objects stored in an ArrayList called inventory. Let's say I have two objects inside.
inventory.add(new Lamborghini(2011, "aventador", 411.3, false));
inventory.add(new Lamborghini(2012, "sesto elemento", 512.3, true));
I am making a function to search through the whole inventory to see if any of the Lamborghini object has a certain model name such as aventador, diablo, etc....
This is what I have but I figured there's a big mistake when I make it true / false; it's making it going through the list and what's return is the last one instead of saying there's such match in the whole list or not.
public boolean hasCarModel(String modelName){
boolean exist = false;
for (Lamborghini lambo : inventory){
String carModelName = lambo.getModelName();
if(carModelName.equalsIgnoreCase(modelName)){
[Code] ....
I figured if I add break; under exist = true; it'll work because as soon as it found one match then it'll turn to true and break out the loop but I don't think this is the best way to do it right?
Using Arraylist Index And Items As Hashmap Key And Values?
Apr 6, 2014I am working on the Kevin Bacon - 6 degrees of bacon problem. I want to take my Array List and use the index and Values that I have saved in it as the Key and Value of a Hashmap. Below is my code.
HashMap<Integer, ArrayList<String>> actors =
new HashMap<Integer, ArrayList<String>>();
ArrayList array = new ArrayList();
try (BufferedReader br = new BufferedReader(
new FileReader("actors.txt"));)
[code]...
saving each one in it's own spot. I want to use the index of each one as the key to find it in the Hashmap....
Check IsEnabled In ArrayList Of JTextFields And Get Text
Oct 9, 2014I have an ArrayList of JTextFields in a CAMSetup1 class that contains a bunch of named JTextFields: Layer_textField_1, Layer_textField_2, Layer_textField_3, ... etc
I would like to check the .isEnabled status of a particular JTextField in that ArrayList from my main class by passing the name of the JTextField to a method in the CAMSetup1 class as a string
The peice of code calling the method from the main class is something like this:
if (CAMSetup1.getFieldEnabledStatus("Layer_textField_1") == true) {
data.writeToFile(CAMSetup1.getFieldText("Layer_textField_2") + " LAYER 2 LIST FILE
");
}
The method for checking the .isEnabled that I have so far is:
public boolean getFieldEnabledStatus(String textFieldname) {
boolean status = false;
//<need code here>
return status;
}
I also need getting the text:
public String getFieldText(String textFieldname) {
String filename = false;
//<need code here>
return filename;
}
JSF :: Finding Index Of Entry In ArrayList - Select Item
Oct 2, 2014I have a JSF application with this code in the xhtml page:
<h:selectOneListbox id="selectProduct" size="10" style="width:10em; font-family:monospace" value="#{mybean.product}">
<f:selectItems value="#{mybean.products}" />
</h:selectOneListbox>
and the corresponding snippets of the Java code are:
// Class member variables
// ...
private String product;
private ArrayList<String> productValues;
private ArrayList<String> productLabels;
private SelectItem[] products;
// ... Various properties etc.
public String getLocation() { // Displayed on a page
[code]....
Most of this works correctly using only ArrayList SelectItem products without the two ArrayList and the separate SelectItem[], and the values and labels are put directly into products here. The menu works and I can select an item. However, I am unable to find the correct method for finding the index in the submit method,namely:
public void submit(ActionEvent e) {
showProduct = true;
prodNum = products.indexOf(product); // --- Here is the problem!
updateProduct();
}
which has not been changed here. In spite of trying out various ideas, prodNum always returns with -1, which means it cannot find the index of the selected product, where product is a String. Everything else seems to work correctly, and products.get(prodNum).getLabel() works if I manually give prodNum a valid index, but because it's -1 it fails.
Read Txt File And Add Words To ArrayList As Strings - Index Out Of Bounds
Apr 15, 2014I have been trying to get this method to work for a few hours now, for some reason I get an IndexOutOfBounds exception every time. Basically I am trying to read a txt file and add the words to an ArrayList as strings separated by a space .
private ArrayList<String> readLinesFromFile(BufferedReader inputFile) throws IOException
{
String value = null;
ArrayList<String> result = new ArrayList<String>();
while((value = inputFile.readLine()) != null){
String[] values = value.split(" ");
for (int i = 0; i < values.length; i++){
result.add(values[i]);
}
}
return result;
}
Create Own ArrayList Using Collection Without Implementing ArrayList Itself
Feb 28, 2014I'm trying to create my own arraylist using Collection. My program doesn't do anything. Obviously, I haven't a clue.
import java.util.Collection;
import java.util.Iterator;
public class MyArrayList<T> implements java.util.Collection<T> {
private int size = 4;
private T[] mArray;
public MyArrayList(String[] args) {
[Code] ....
Check For Win In Tic Tac Toe
Nov 25, 2014I am having trouble figuring out how to check for win in tic tac toe, the way my teacher wants it is with various if statements but im not sure what to put in the parentheses. I think it would be something like
if(button==button.getIcon(x)) {
if(button2==button2.getIcon(x)) {
if(button3==button3.getIcon(x)) {
playerWon=true;
player2Won=false;
}
}
}
This is what i have so far
import java.awt.Container;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class TicTacToe extends JFrame implements ActionListener
[Code] .....
Populating ArrayList Object With Nested ArrayList Object
Jul 8, 2014I have stumbled onto a problem with ArrayLists (not sure if nested ArrayList objects would be a more accurate description) ....
As simply put as I can describe it, I have an Inventory class which creates an ArrayList of a Product superclass, which has two subclasses, PerishableProduct and ItemisedProduct.
By default, the program is meant to have a starting inventory, which is why I have added them in the constructor
public class Inventory {
private List<Product> products;
public Inventory() {
addProduct(new Product("Frying pan", 15, 20));
addProduct(new PerishableProduct("Apple", 5.8, 30, 7));
addProduct(new ItemisedProduct("Cereal", 5.8, 0));
// this is where I am having problems. Wanting to add
// objects to the ItemisedProduct's ArrayList for cereal.
}
Within the ItemisedProduct subclass is yet another ArrayList which is meant to hold serial numbers.
public class ItemisedProduct extends Product {
private ArrayList<String> serialNumbers = new ArrayList();
public ItemisedProduct(String name, double price, int qty) {
super(name, price, qty)
[Code] .....
My problem is that I do not know how to populate the serialNumbers ArrayList from the Inventory class' constructor. Because technically, quantity is defined by how many serial numbers are created.
JSF :: Row Index In UI - Repeat Tag
Feb 7, 2009I am using ui:repeat tag to iterate over a list. Now in that I need to do some processing based on the current iteration index like we have in a normal for loop. I have to do some processing based on the current iteration index. How can I get that.
View Replies View RelatedHow To Check Array
Oct 19, 2014This SHOULD be a simple program, the gist of it is Given an element E and the array A that represents a set X (user input), write a program that determines whetherE is an element of X.I have the array list all set up to take the user input and make zero the last element of the array. I want user to input numbers into array, then have fixed numbers for E and check to see if E is in the Array. I guess I'm not sure how to check the array and see if E is in the array? Here is what I have so far...
import java.util.ArrayList;
import java.util.Scanner;
import java.util.List;
import java.util.InputMismatchException;
public class Set {
public static void main(String[] args) {
List<Integer> userInputArray = new ArrayList<Integer>();
[code]...
Index Out Of Bounds
Oct 17, 2014Code is supposed to count number of Words in a String between A-Z and a-z, i am aware there are many methods to do this more efficiently, but i would prefer to do it using the methods shown.
class
// Purpose : 1) Write a program which will input a string from the
//keyboard, and output the number of separate words,
//where a word is one or more characters separated by
//spaces. Your program should only count as words groups
//of characters in the ranges A..Z and a..z
//
{
public static void main(String args[])
[code]....
GUI When Selecting Check Box
Jul 9, 2014I am having an issue with my swing gui. I dynamically create tabs with information (textfields, checkboxes, combo boxes) and when I select the checkbox it disables or enables a textfield. Now when I select the checkbox it seems to resize everything, specifically my textfields from say 9 columns to probably one. I"m a little unsure why it is doing this but I have a feeling it may be an inheritence issue.
My code is below for my generation of the tabs and of the rest of the information on the gui. The gui is an inner rid layout with a top and bottom pane that are both gridbaglayouts and an outter pane as well. I am thinking I am missing something in the grid layout setup that is causing this.
private void initComponents() {
jTabbedPane1 = new javax.swing.JTabbedPane();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
getContentPane().setLayout(new java.awt.GridLayout(1, 0));
pack();
[code]....
JSP :: Check Box Implementation
Sep 30, 20141. In jsp 1 , i have 3 checkboxes(chkbox1,chkbox2,chkbox3) , if i select check boxes (chkbox1, chkbox2), and click on submit, corresponding two text fields (chkbox1,chkbox2) will have to appear in the next jsp i.e., jsp 2.
2. In jsp 1 , i have 3 checkboxes(chkbox1,chkbox2,chkbox3) , if i select check boxes (chkbox2, chkbox3), and click on submit, corresponding two text fields(chkbox2,chkbox3) will have to appear in the next jsp i.e., jsp 2.
Like this, which ever checkbox i select, corresponding text fields should appear in the subsequent jsp.
How To Check If At Least One Number In A String Is Different From 0
Nov 18, 2014I'm trying to come up with a method that would validate each turn a player makes. For a turn to be valid, it has to only contain numbers from 0 to 3(inclusive) and at least one digit must not be 0. Here is what I`ve come up with so far. For example, with "303" as the number and "101" as the turn, the turn would be valid and my method should return true, but it does not.
public static boolean turnIsValid (String number, String turn ){
boolean rep=false;
int pos1=0;
char min='0';
char max='3';
while(number.length()==turn.length()&&pos1<turn.length()){
[Code] ....
Array Index Out Of Bounds
Oct 21, 2014import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.*;
import java.awt.event.*;
[Code] ......
Just cant see where the array is out og bounds the array ButtonList has 9 buttons....
Printing Out String Out Of Index?
Jan 24, 2014I am writing a Java permutation program, it takes in N and k and gives k amount of combinations based on N length.
That portion works, but the portion I have that does not work is when k is greater then 1, the array is then then printing strings out of index.
The perm algorithm ends on index - 1 for moving characters but then I push all those characters into an Array List, I would think I could print them off however I want from there but that is not the case. I'll include the minimum amount of code possible.
//permString = 1234 or something, it doesn't matter
//Use Case N = 4 k = 3, prints out 123,124,132,134 ect
//Use Case N = 4 k = 2, error index out of range but only on the printing function; the perm function doesn't take k and
//is based on length
//the "" is just an empty string
permNow("", permString);
}
[code].....
How To Check Regular Expression
Aug 25, 2014I have to match pattern like 76XYYXXXX mean x can be 4or 5 and Y can be 6 or 7. All x and y should be same .i.e. 764664444
View Replies View RelatedJSF :: How To Check Condition In Xhtml
Mar 26, 2014I need to display button based on the condition in xhtml page.
using JSF2 & richface 4.0
<c:forEach items="#{empList}" var="emp">
How to check condition like empList.size > 0 in xhtml?
if list is having value, need to show buttons.
Getting The Index Of A Matrix Of Buttons
Dec 7, 2014I am attempting to get the x and y coordinate of a matrix of buttons. I have googled my way to failure and read the docs and I think I am traveling of track.
Below is where I create a matrix of buttons via Swing
public class View extends Mybuttons{
private static final long serialVersionUID = 1L;
JFrame frame;
JPanel matrixPanel, optionsPanel;
Mybuttons[][] matrixBtn;
Later in this class:
JPanel matrixPan(){
matrixBtn = new Mybuttons[25][25];
JPanel panel = new JPanel();
panel.setSize(550,550);
panel.setLayout(new GridLayout(25,25));
//creating a 25x25 matrix of buttons
[Code]...
In the controller class I am trying to get the index of each button in the getUnvisitedChildNode method. I need to do this so I can search the buttons around the button passed to it and check if they are been visited yet. Below getUnvisitedChildNode you will be bfs (breadth first search).
private Mybuttons getUnvisitedChildNode(Mybuttons b){
//example of some of the things I have tried
int x= Mybuttons.getComponentAt(b);
int y= Mybuttons.indexOf(b);
int j=0;
return b;
}
[Code]...
String Index Out Of Bounds?
Feb 6, 2014Ok, so I'm just trying to write a basic little program that reverses the letters in someone's name. I thought I had it down, but I guess not. Here's the code, and the error I'm getting is:
java.lang.StringIndexOutOfBoundsException:
String index out of range: 11 (in java.lang.String)
(11 is the length of the name I'm inputting)
import java.io.*;
import java.util.*;
[code]....