Array Lists - Adding New Elements
Apr 1, 2014
I am working on a assignment that has to do with array lists, it mainly has to do with adding new elements, telling then where it is it located, if the memory block is empty , ect. so far i have been having problems with my indexOf method which should display the array cell number that a input element E is in, and if it is not in there it should display a -1.
public class MyArrayList<E>
{
private E[] data_store = (E[])new Object[2];
private int sizeofa = 0;
private void resize()// makes the array list bigger if need {
E[] bigspacemaker = (E[])new Object[data_store.length * 2];
for(int x = 0 ; x< sizeofa ; x++)
[Code] ....
Error message:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 512
at MyArrayList.indexOf(MyArrayList.java:28)
at MyArrayListDemo1.main(MyArrayListDemo1.java:26)
View Replies
ADVERTISEMENT
Feb 5, 2015
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class array
{
public static void main(String[] args)
[Code] ...
Is there a way to write this, where, alpha is one array.
Write a program that declares an array "alpha" of 50 elements of type "double". Initialize the array so that the first 25 elements are equal to the square of the index variable and the last 25 elements are equal to three times the index variable. Output the array so that 10 elements per line are printed.
If I have an array of 50 integers, can I break that to read in lines of 10?
View Replies
View Related
Feb 6, 2014
Here is a small part of my program
Java Code:
// for every attribute not mentioned in the rule r
enumAtt = ruleE.enumerateAttributes();
while (enumAtt.hasMoreElements()) {
Attribute attr = (Attribute) enumAtt.nextElement();
if (isMentionedIn(attr, r.m_test)) {continue;}
int M = attr.numValues();
[Code] ....
It repeats only the last rule , why is that !!!!!!
View Replies
View Related
Jan 12, 2015
I am trying to make a 2d array that keeps track of comparison counts. what I have so far works ok but writes over the previous elements with 0. can't seem to find where I am re-initializing the previous elements.
//this is one of my fill sort arrays
public void fillSelectionArray(int index, long countSum) {
//rand = new Random( );
//for ( int i = 0; i < listsize; i++) {
selectionList[ index -1] = countSum;
// }
[Code] ....
I know I am missing something just not sure what.
View Replies
View Related
Mar 14, 2014
I know there was a change in the later versions of Java where the C++ equivalent of a <template type> was added. Unfortunately the change has 'broken' my older code. If I have a JList and I want to add elements to it then now I should specify the type e.g., the list will store Strings. When I do this and then add data to the list (or actually the list model) the code is ''fixed". However if after adding those new elements to the list I later need to add more elements, which isn't unreasonable for a list...to have elements added dynamically at run time then I again get the same compiler error message that I haven't correctly specified the type:
// Error message during compilation
Note: Driver.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
// My code
// Problem here: I try to add new elements to the list. It's the very last line of the method that results in the error. I tried various things such as:
// model.addElement(<String> s);
// but so far nothing has worked. How do I add new elements to the list (model)?
public static void m2(JList <String> list)
{
String s;
int i;
String [] array = new String[10];
[Code] ....
// Code is OK: Create the array of strings to add to constructor of the JList
public static String[] m1(){ String s;
int i;
String [] array = new String[10];
for (i = 0; i < 5; i++)
array[i] = i + "*"; return(array);
[Code] ....
// The change I had to make when compiling under the newer version of Java to indicate that the list would store strings
// Things are okay here now but then when I try to add new elements to the model via method 'm2' that's where I get the compiler error
View Replies
View Related
Dec 6, 2014
What is going on here in the main class is a zoo that requires information to be read from and saved to a .txt file. I have made three arrayLists for each .txt file, I am getting errors for illegal start to an expression
import java.io.*;
import java.util.*;
public class ColumbusZoo
{
public static void addHelper(ArrayList<DomesticAnimal> a){
Scanner s = new Scanner(System.in);
System.out.println("What species");
[code].....
View Replies
View Related
Nov 21, 2014
I need comparing two array lists. For this program i am comparing 2 array lists. The list is integers entered by the user the second is random generated numbers. So far in my program i am able to compare the 2 arrays together and output if they are equal or not however i need the program to output even if atleast one if the integers match,
EXAMPLE list one: 1, 2 ,3 ,4, 5. LIST TWO: 1, 3, 3, 3, 3.
Since the first number matches i want it to out put there is one match, so on and so forth with if there are 3 or 4 matching integers. here is my code so far.
public static void main(String[] args)
{
final int NbrsEntered = 5; //Number of guessed numbers entered
final int LOTTOnbr = 5;
int[] numbers = new int[NbrsEntered];
int[] randomNum = new int[LOTTOnbr];
//int[] TestArrayOne = { 1, 2, 3, 4, 5 };
//int[] TestArrayTwo = { 1, 2, 3, 3, 5 };
boolean arraysEqual = true;
int index = 0;
[Code] ....
View Replies
View Related
Mar 24, 2015
I am taking the Class Algorithms and Datastructures and got an assignment for Lab that really throws me off. The goal is to create an Array out of a given CSV file, implement several Methods that get the size of array, etc.
I am still stuck in the first part where the CSV has to be imported into the Array. My problem is that I need a mechanism that figures out the needed size for the Array, creates the array, and only then transfers the data from the CSV.
The list consists of the following wifi related values:
MAC-Adress, SSID, Timestamp, Signalstrength.
These are on the list, separated by comma. The Columns are each of these, and the rows are the four types of values making up the information on a certain wifi network.
The catch is, we are not allowed to use any of the following:
java.util.ArrayList
java.util.Arrays
and any class out of java.util.Collection.
So far I used the BufferedReader to read in the file and tried to implement the array, but I get an arrayindexoutofboundsexception.
Below is my Code (Its still an active construction zone):
public class WhatsThere {
public WhatsThere(String wifiscan) throws IOException {
}
public static void main(String[] args) throws IOException {
// WhatsThere Liste = new WhatsThere(String wifiscan);
String[][] arrayListe = new String[0][0];
[Code] ....
View Replies
View Related
Apr 19, 2015
I'm working on an assignment that asks for the user to input 2 lists of numbers and my program will merge and sort the lists using arrays and 2 methods. I think I have most of it down, but I'm not sure how to go about getting the user inputs. In my current code, it's giving me a bunch of 0s instead of a sorted list.
import java.util.Scanner;
public class merge2sortedlists {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
[code]....
View Replies
View Related
Mar 14, 2015
For example, if I had a text file with one line such as "first, second, third", would there be a way to make it so I could make "first" go to the first array list, "second" to the second, and "third" to the third?
I haven't posted any of my code so far as it wouldn't be right to be handed the finished code on a platter and I should put the work into it, but I'd just need a loop to make it go through the rest of the lines in the text file to add all the first, second and third parts of each line, right?
(I already know how to input data from a file, but not how to split up a line into bits to put into different array lists).
View Replies
View Related
Jan 22, 2015
When I insert: title, category, year, artist in 4 Strings And when I press "enter" i put those 4 in a array "large", and then when I can start a new music insert with 4 new string elements and add those in the large array..So: I have an array "large" with the length 19 (or so..)(max ~100 or so)Then I what to: get,in a new array "title",the elements:0,4,8,12,16 (from the large array) and put them in a scrollable list. And when I select one element in the title array I then whant to get 3 remaining elements from this. And put it in a array called selection.
So the "large" and the "title" arrays must be dynamically sizes... or be copied to a larger sized..
1 can it be done with arrays?
2 how do dynamically change the size of for example the array "title"?
3 how do I receive the elements 0,4,8,12,16 and so on, (to (
large.length-3) and add it to the title array?
View Replies
View Related
May 4, 2015
What is the sum of the array ar elements after executing the following code?
int[] ar = {1,2,3,4,5};
for (int i=0; i<ar.length-1; i++)
if (i%2==0) ar[i]=i;
My professor says the answer is 12 i dont know how he got that answer
View Replies
View Related
May 17, 2014
I cant get this code to work if wont find the right min and range and its printing out my max three times . This is what I got
public static void main(String[] args)
{
double [] Rainfall = new double[12];
Rainfall[0] = 77.4;
Rainfall[1] = 56;
Rainfall[2] = 61.8;
Rainfall[3] = 62.1;
Rainfall[4] = 57.1;
[Code] ....
View Replies
View Related
Mar 29, 2015
I have two arrays
private ReservedBook[] reservedBooks;
private LibrarySystem[] libraryBooks;
The library array has two books and I want to copy one of them to the reserved books when you type in the ISBN
public void borrowBook(String ISBN)
{
int i = 0;
if(numberOfBooks < MAX_BOOKS-1)
{
if(libraryBooks[i].getBookISBN().equals(ISBN))
{
for(i=0;i<MAX_BOOKS-1;i++)
reservedBooks[i] = libraryBooks[i];
}
else System.out.println("There is no such book");
}
else System.out.println("You have reached the maximum number of allowed books");
}
It shows me error: incompatible types - LibrarySystem cannot be converted into ReservedBook. How can I fix it?
View Replies
View Related
Oct 27, 2014
So I am trying to create a code that searches if a word is square free. The user inputs a word (into an array) and then the code is suppose to see if it is square free. A word being square free means that the word doesn't contain any consecutive sub words. For example, "abcabc" is not a square free word because abc is repeated, but "abcdabc" is a square free word because there is a "d" separating the "abc".
So far I have this :
import java.util.Scanner;
public class A3Q2 {
public static void main(String[] args) {
// part (a) of the main
Scanner keyboard = new Scanner(System.in);
[Code] ....
I've been trying to experiment with different ways such as checking to see if there any duplicate elements such as,
public static char isSquareFree(char[] word){
for(char i = 1; i < word.length; i++) {
if(word[i] == word[i - 'a']) {
System.out.println("Duplicate: " + word[i]);
}
}
return word; }
}
And other methods but I'm just not getting it.
View Replies
View Related
Oct 15, 2014
I have tried to print array elements using standard print statement. I am getting errors. How to print them. Here is my code:
class arrayEx1{
public static void main(String args[]) {
int a[]=new int[3]; //Declaring Single Diomentional Array
a[0]=10;
a[1]=20;
a[2]=30;
int total=a[0]+a[1]+a[2];
System.out.println("Values stored in a[0],a[1],a[2]elements are :" + a[0] a[1] a[2]);
System.out.println("Total values of a[0],a[1],a[2]elements is :"+ total);
}
}
if i give comma (,) in between above print stament (print statement 1) stil i am getting errors.
View Replies
View Related
Mar 20, 2014
public class werek4d {
public static void main(String[] args) {
int counter = 1;
int[] anArray = new int[101] ;
for (int i = 0; i <= 99; i++){
anArray[i] = i + 1;
System.out.println(i + ": " + anArray[i] + " ");
[Code] ....
My aim is to generate a lists containing 1 to 100. I will then count the number of integers divisible by 3. After doing so, I want to delete the integers that are NOT divisible by 3 in the lists. I tried doing it, but I seem to keep on getting the same lists.
View Replies
View Related
May 24, 2014
If I have a boolean array that contains 30 elements (boolean[] fish), how do I go about isolating every 10 elements to use for something specific?
Say there are 30 types of fish stored within the boolean array and 0-9 are fish found specifically in the Indian Ocean, 10-19 are fish found specifically in the Atlantic, and 20-29 are fish specifically found in the Pacific Ocean. And for those 10 fish [0-9], [10-19], [20-29], each is a different color (red, orange, green, blue, white, black, silver, yellow, purple and gold), where the colors and locations of the fish are enum types Colors and Locations.
How do I go about appointing those characteristics to the fish?
Ex: elements [0-9] are fish from the Indian Ocean and [0] is red, [1] is orange, [2] is green, [3] is blue, [4] is white, [5] is black, [6] is silver, [7] is yellow, [8] is purple, and [9] is gold.
elements [10-19] are fish from the Atlantic Ocean and [10] is red, [11] is orange, [12] is green, [13] is blue, [14] is white, [15] is black, [16] is silver, [17] is yellow, [18] is purple, and [19] is gold.
elements [20-29] are fish from the Indian Ocean and [20] is red, [21] is orange, [22] is green, [23] is blue, [24] is white, [25] is black, [26] is silver, [27] is yellow, [28] is purple, and [29] is gold.
Will I need to appoint those characteristics in the constructor after initializing fish = new boolean[30]?
View Replies
View Related
Oct 27, 2014
This is my code for the driver class:
import java.util.*;
public class SavingsAccountDriver {
public static void main(String[] args) {
System.out.printf("%10s%10s%10s%10s%10s" , "Month" , "Account #" , "Balance" ,
"Account #" , "Balance");
[Code] .....
Here is the output I get :
Month Account # Balance Account # Balance
----- --------- ------- --------- -------
0 10002 2000.00 10003 3000.00
1 10002 2002.00 10003 0.00
2 10002 2004.00 10003 0.00
3 10002 2006.01 10003 3030.00
4 10002 2008.01 10003 0.00
5 10002 2010.02 10003 0.00
6 10002 2012.03 10003 3060.30
7 10002 2014.04 10003 0.00
8 10002 2016.06 10003 0.00
9 10002 2018.07 10003 3090.90
10 10002 2020.09 10003 0.00
11 10002 2022.11 10003 0.00
12 10002 2024.13 10003 3121.81
Why is it not showing those months updated balance? I feel like I'm pretty close. I guess I should specify that this is supposed to calculate monthly interest for one account and quarterly interest for the other. This is what the output should look like.
Month Account # Balance Account # Balance
----- --------- ------- --------- -------
0 10002 2000.00 10003 3000.00
1 10002 2002.00 10003 3000.00
2 10002 2004.00 10003 3000.00
3 10002 2006.00 10003 3030.00
4 10002 2008.01 10003 3030.00
... ... 12 ... ...
The quarterly interest is the one that is giving me trouble.
View Replies
View Related
Jul 16, 2014
I have the simple table below:
currency amount
€ 2.0
$ 4.0
£ 5.0
How could I store the currency and amount in an array? A 2x2 array would do this but how to store them and retrieve them is the challenge. For example, I have a method that asks the user for two inputs, the currency and the amount and using the array as a chat table where I could map the currency to the the currency input entered by the user, I could do some calculations with the amount entered by the user. how I could represent the 2x2 array?
View Replies
View Related
Dec 18, 2014
I was trying remove duplicates element from my array without using collection API but i didn't got any output from my code.Although it is compiled successfully but on execution it didn't give any output. I guess there must be some problem in function Duplicate
Java Code:
class Union {
public static void main(String...s) {
Union M=new Union();
int x[]=new int[]{1,0,1,4,10,10,10,3,567,4,3,33};
int y[]=new int[]{5,4,5,4,5,4,2,3,3,1,0};
int []w=M.merge(x,y);
[Code] .....
View Replies
View Related
Jan 27, 2014
You are given an array A with elements 0 to n-1, numbers can be repeated in the array. Create n sets where
S[i]={a[i],a[a[i]],a[a[a[i]]]...}.
Set has all elements unique. Find the size of the largest set.
Input:
First line contains n, size of the array. n<1000
Next lines contains n numbers, each element of the array
Output :
Prints one number: Size of the largest set.
Sample Test Case:
Input: {3,1,2,0}
Output: 2
Explanation:
Four possible sets are
{3,0},{1},{2}{0,3}
View Replies
View Related
Jan 6, 2015
B is an array Object, as you can see if an element is null or not?
View Replies
View Related
Dec 17, 2014
In my project I need to create a pizza ordering system. I have created a array list of pizza toppings and each pizza topping must have a cost property associated with it, then the user can pick the toppings they want and the cost of each topping will be added up and the total cost of the whole pizza will be displayed. But I don't know how to associate a cost with each topping. I have been told that I can access the cost through a get/set method and store it in a private member variable. But I don't know how to do this?
I've tried to do it, but it hasn't worked. This is the code
public void setCost( double cost){ //my get/set method
this.cost = cost;
}
public double getCost(){
double price = 0;
return price;
[Code] .....
But there is an error on each of the ingrediantCost method lines, saying
The primitive type double of cost does not have a field Pepperoni
...and the same for chicken, ham and onion.
View Replies
View Related
Sep 11, 2014
If you see in the code below where I print "Would you like to use previous key" I need to be able to save the previous key answers to be used again.. not sure how to go about doing this..
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
String[] studentName = new String[20];
int[] studentAverage = new int[20];
Scanner input = new Scanner(System.in);
[Code] .....
View Replies
View Related
Apr 30, 2014
remove duplicate elements in array using with java
View Replies
View Related
