I come to the point: I just started to learn java through various manuals and in one of them I came across a declaration of an array that I do not understand:
int[][] multiArr = new int[2][];
the manual says that you can allocate the multidimensional array multiArr by defining size in only the first square bracket but I can't undestand how you can use this array. Seems to be no way to store data with it!
what would the return be for adding two array's together,
public static int sum (int[][] a, int[][] b) {
int[] [] c = new int[a[0].length][b[0].length];
for (int i=0; i< a.length; i++){
for (int j=0; j<a[i].length; j++){
c[i][j] = a[i][j] + b[i][j];
}
}
return c[i][j];
}
My return is wrong...... I know, Any hints?
At the bottom of this code snippet you will see the print statement. I am trying to divide the multidimensional array by its sum. Can this be done simply in the System.out statement, or do I need a separate method?
private static void Histogram() throws IOException {
int[][][] ch = new int[4][4][4]; /* 4 for 64 and 8 bins, 8 for 512 bins */
BufferedImage image = ImageIO.read(new File("airplane_training1.jpg"));
for(int x = 0; x < image.getWidth(); x++)
for(int y = 0; y < image.getHeight(); y++) {
[Code] .....
import java.util.Scanner;
public class ColumnSum {
public static void main(String[] args) {
Scanner s = new Scanner (System.in);
int userpick = 0;
int sum = 0;
int [][] matrix = {{5, 9, 87, 74, 12, 7}, // row 1
[code]...
Right now my code gets all the numbers in a row and adds those up, but I want it to get the numbers in a column and add them instead. The problem is I don't know how to get the userpick (the number that the user picks to determine which column gets added) to be set to that particular column.
I tried this:
String[][]f = new String[1][1] {{"Harry"}{"Hairy"}};
I also tried this:
String[][]f = new String[1][1] {{"Harry"},{"Hairy"}};
but I get an error
public class StuTest {
private static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args){
int[][] testScores; // [students][tests]
String[] stuNames;
[Code] ....
The method I am having issues with is the "printStudentReport" method. I am trying to calculate the average of a randomly generated number of students and tests. For my "printTestReport" method, I have to calculate the average of the test by test number.
I've found different examples on line, but none that use the split method with a multidimensional array. I would like a user to input coordinates (x,y) for city locations and store them into a 2-D array. For the user to input the x,y-coordinates on one line I need to use split(',') and then parse the string array to a double which will then be used to calculate the distances from one another.
My issue is how to store the String vales into the 2-D array. I do not want to store the x-value at even (cityArray[0]) and y-value at odd (cityArray[1]) 1-D locations.
I want to print each value in the multi-dimensional array using a for loop but there is a problem.
Here is the script:
Java Code:
public class LearningJava
{
public static void main(String[] args) {
int[][] Grid = {
{12, 24, 36, 48, 60},
{1, 3, 5},
[Code] ....
Printing i: 0, x: 12
Printing i: 0, x: 24
Exception in thread "main" Printing i: 0, x: 36
Printing i: 0, x: 48
Printing i: 0, x: 60
java.lang.ArrayIndexOutOfBoundsException: 5
at LearningJava.main(LearningJava.java:11)
It's suppose to get the length of each array and print all the values in that array and then move to the next one.
I tried adding .length
Java Code: for(int x = 0; x < Grid[i][x].length; x++) mh_sh_highlight_all('java');
but then it doesn't work at all.
I have to write a program that will read a picture and then print out the number of blocks inside it.I have to read the picture as a binary matrix of the size r c (number of rows times number of columns).The blocks are groups of one or more adjacent elements with the value 1.
- Blocks are built exclusively of elements with value 1
-Each element with value 1 is a part of some block
-Adjacent elements with value 1 belong to the same molecule.
We only take into account the horizontal and vertical adjacency but not diagonal.
INPUT:
In the first line of the input we have the integers r and c, separated with one space. Then we have the r lines, where each contains s 0's and 1's.The numbers inside the individual lines are NOT separated by spaces.The OUTPUT only print the number of blocks in the picture.
Example:
INPUT:
7 5
01000
00010
00000
10000
01000
00001
00100
OUTPUT:
6
THIS IS WHAT I CAME UP SO FAR:
import java.util.Scanner;
class Blocks{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
[code]...
how you can do array.length, I have an array with [][][][], and what do I do to find the length of one section?
So let's say
Java Code: int array[][] = {
{5, 5, 5, 5},
{4, 4, 4, 4},
{3, 3, 3, 3}
} mh_sh_highlight_all('java');
How do I find out the length of the {5, 5, 5, 5} which is 4. Because there are 4 place-holders.Is there a way?
I have a file which contains certain positions ([a][b]) that require to be placed in a certain multi-dimensional array. For example I might have an array String[][] that is a size of 6x6 but only have values in positions [2][1] and [3][2]. Because it is important for me to maintain the given array size and also do certain actions with the given positions I cannot modify the size. In addition I need to count the surrounding neighbors each element has (including elements that are null). However because some of my further code cant process with null elements I need to remove all null elements with " " (blank).
I am not sure how this is done or if it's even possible. If it is not possible how can I do something as close as possible to my needs?
I am working on a project on bluej called battleship and being new to it I cant figure out how to generate a ship(3 co ordinate long) on a 10X10 multi dimensional array. nothing graphical just plain co ordinates.
View Replies View Relatedimport java.util.*;
import java.text.*;
public class Linearize {
public static void main(String[] args) {
// Create new Scanner and Random and Decimal objects
Scanner s = new Scanner (System.in);
Random g = new Random ();
DecimalFormat oneplaces = new DecimalFormat (".00");
[code]....
I am really close to finishing this program and my output is almost there, except it's only printing out the first half or so of the array. I have two for loops and two counters to determine the size of the array and then copy the multidimensional array's values into the 1D array, but it only prints out the first half of the array as such:
How many rows in the array? 4
How many columns in the array? 2
This 2D array contains:
35.23, 26.94,
99.48, 66.69,
7.31, 25.18,
64.53, 21.25,
Converted to a 1D array:
35.23, 26.94, 99.48, 66.69,
And yes, I realize that I should be formatting my Print statements with % but my instructor doesn't seem to care about it (he never taught it to us) so for the time being I am being stubborn and using .
I am trying to write a code for multidimensional array, allocate memory for variables and access the value of the arrays. I want them to be shown as rows and columns. but my code only shows one column and no rows. here is my code:
public static void main(String[] args) {
int[ ][ ] aryNumbers = new int[2][2];
aryNumbers [0][0] = 1;
aryNumbers [0][1] = 2;
aryNumbers [1][0] = 3;
aryNumbers [1][1] = 4;
int rows = 2;
int columns = 2;
[code]....
I have been asked to write a library program that will keep record of books and the year it was published. The program should ask the user how many rows he wants accept the string input from the user and display them in rows and columns. This is how i code it
package multidimension;
import java.util.Scanner;
public class bookrecords {
public static void main(String[]args){
//declaring a scanner variable
Scanner input =new Scanner(System.in);
[code]....
I just started in java programming and into Arrays multidimensional. I started a simple 2 dimensional array with 5 names with genders. I 'm having issues because it does not want to print out the names with correct genders Male/ Female. The simple program should print out the 5 names with gender type.
example:
Jack - Male
Sally - Female
Dave - Male
Sue - Female
Brian - Male
Here is what I came up with so far:
public class Multiname
{
public static void main(String[] args)
{
//String[][] multiname;
String [][] multiname =
[Code] .....
This is the result:
multiname : Jack
multiname : sally
multiname : Dave
multiname : Brian
multiname : Sue
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1
at MultiD.main(MultiD.java:29)
I'm trying to create a cursor for a game that moves square by square. While it will move to the next square, though, it leaves the image of the previous cursor on the last square it was on.
As a visual explanation, this is what the program looks like on launch:
This is what it's suppose to look like after you press the right arrow key once (made by forcibly changing launch coordinates):
And this is what it actually looks like after you press the right arrow key once:
Here is the code for the program:
package cursortest;
import javax.swing.*;
import java.awt.*;
import javax.imageio.*;
import java.io.*;
import java.awt.event.*;
public class CursorTest extends JPanel implements KeyListener{
[Code] ......
I'm fully aware that I could just use g.clearRect on the area and remove it for sure, but I know for a fact I shouldn't have to as I have another program I made a long time ago that tried to do something similar without needing to resort to that.
I have to write a program that will read a picture and then print out the number of blocks inside it.
I have to read the picture as a binary matrix of the size r - c (number of rows times number of columns). The blocks are groups of one or more adjacent elements with the value 1.
- Blocks are built exclusively of elements with value 1
- Each element with value 1 is a part of some block
- Adjacent elements with value 1 belong to the same molecule.
We only take into account the horizontal and vertical adjacency but not diagonal.
INPUT:
In the first line of the input we have the integers r and c, separated with one space.
Then we have the r lines, where each contains s 0's and 1's.
The numbers inside the individual lines are NOT separated by spaces.
The OUTPUT only print the number of blocks in the picture.
Example:
INPUT:
7 5
01000
00010
00000
10000
01000
00001
00100
OUTPUT:
6
THIS IS WHAT I CAME UP SO FAR:
import java.util.Scanner;
class Blocks{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
char ch[][];
int rowNum=sc.nextInt();
int columnNum=sc.nextInt();
[Code] ....
How would I compare the square of the square root of any number. The difference in these values is due to the rounding error in Java.
Example: Enter number 2
The answer I should get is: 2.000000000000004
Round off error: -4.440892
How to create a MAGIC SQUARE, i just wanted to learn the logic of it .. with 2d array and looping..
View Replies View RelatedI 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] ....
I have the textfile which has lines:
A B 2 midterm 100
C D 1 final 90
C D 1 midterm 90
A B 2 final 80
**NO ARRAYLIST IS ALLOWED!** And the textfile is passed into the method. How to get the size for the array non-randomly inside the method from the passed Scanner file?? What if you have lots of numbers of lines, so how could that be done?
I have doubts about this line Exam[] object = new Exam[12];
Java Code:
public static Exam[] readAllExams(Scanner s) throws ArrayIndexOutOfBoundsException
{
String firstName = "";
String lastName = "";
[Code].....
The array size is fixed improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array into it .I am using a course class and here is the code for the class
public class Course {
private String courseName;
private int numberOfStudents;
private String[] students = new String[100];
public Course(String courseName)
[Code] ....
As you can see I have the array set to size 100, how do i make so it increments each time the user adds a student.
I'm working on an assignment that says the following.
" The array size is fixed in Listing 10.6. Improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array to it.Implement the dropStudent method.Add a new method named clear() that removes all students from the course.
Write a test program that creates a course, adds three students, removes one, and displays the students in the course."
10.6 Listing
public class Course {
private String courseName;
private String[] students = new String[100];
private int numberOfStudents;
}
public Course(String courseName) {
this.courseName= courseName;
[Code]...
My Test Code based off of book
public static void main(String[] args) {
Course course1= new Course("Business");
course1.addStudent("Jay");
course1.addStudent("Silent Bob");
course1.addStudent("Dante");
course1.dropStudent("Jay");
[Code]....
My adjusted 10.6
public class Course {
private String courseName;
private String[] students = new String[100];
private int numberOfStudents;
}
public Course(String courseName) {
this.courseName= courseName;
[Code]...
The problem I'm having is, for the first part of the question where I need to automatically increase the array size. I'm really not great at this stuff. I have tried breaking it down, but can't "get it", I guess.
I assume, it'd be a loop that checks to see if the student array is full and if so, do the increaseArray() part, by maybe multiplying the student array and then assigning it. I just don't know how to do it haha.
My *best* attempt at the loop so far has been
if (students == students.length){
int bigArray = 2*students.length;
String increaseArray()= new String[students];
System.arraycopy(students, 0, increaseArray, 0, students.length);
students= increaseArray;
but,yeah... Doesn't seem to be right.
I am having trouble with an assignment. I need the user to input the size of the array and print when asked. In my program, it prints 100 numbers instead of the user input number, such as 15.
import java.util.Arrays;
import java.util.Scanner;
import java.util.Random;
public class Lab9 {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int [] values = new int [100];
[Code] .....
I am trying to make a code that copies the users String to a char array. However, I am in a predicament: since I would not know the exact size of the users String I am left with the options of either making my array large by default, filled in with, lets say 25, empty spaces per index OR starting out with a default size of 1, with an empty space, and then some how increase the size from there.
At this moment I am leaning on the first option, creating a large default array and then deleting the unused values. However, this brings me to my actual question: if I set the non used indexes to null, if that wont give me an error, would that change the size of my array?
Ex:
//lets say i finally copied all of the values and this is the result
char[] word = {'b', 'o', 'b', ' ', ' '};
for(int i = word.length(); i > 0; i--){
if(word[i] == ' ')//delete the value so the size decreases
word[i] = null;//if possible
}