I have written following code.
I want to print all elements in Array to output here is my code
int[][] arr={{12,12,13},
{14,1223,14}};
for(int i=0;i<arr.length;i++)
{
for(int j=0;j<arr.length;j++)
{
System.out.println(arr[i][j]);
}
}
but I am getting following output
12
12
14
1223
how to print all elements of int array?
I have a 2 dimensional array assignment with a loop, i'm supposed find the average score of each student from a grade record and find the average score for each test. I've been trying to do the assignment all day with no progress. This is what i have so far
public class SiuTest {
public static void main(String[] args) {
String [] stu= new String [5];
int [] [] grade= new int [4][2];
String hold;
[code]....
Started learning about Array's I'm doing an exercise where you create a for loop that randomly assigns values to each element within the array, but where is my code going wrong?
import java.util.Scanner;
public class ArrayExamples{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double exampleArray[] = new double[5];
System.out.print("Enter a Number: ");
int num1 = input.nextInt();
[Code] .....
I mainly would like to know is a int[4][4] or a int [4*4] is more efficient to use. Which takes more storage? Which requires more to process? that kind of stuff.
View Replies View RelatedI have a problem with multi threading calling with for loop. I have those two and many other classes in one jar file but n 2 different packages.
When i execute the jar file first runs the Aclass, from where i try to run multi threads. From the run() of the class RunTheGame i call many other classes which are in the same package. Like you can see from the for loop is executed the threads.
The problem is that when the second thread starts the first one is stopped this happens for all the threads, more simply when a new thread starts the old one is dead.
It seems that liken the threads uses the classes called from run() of the class RunTheGame as non multi threaded. It gives this error:
Java Code:
Exception in thread "Thread-0" java.lang.NullPointerException
at thePackage2.EClass.getWhiteRemaining(EClass.java:49)
at thePackage2.EClass.isFinal(DClass.java:84)
at thePackage2.Spiel.<init>(Cclass.java:76)
at thePackage2.RunTheGame.run(RunTheGame.java:198)
at java.lang.Thread.run(Thread.java:745) mh_sh_highlight_all('java');
All the above refereed classes are called from the from run() of the class RunTheGame . Like i understand all the threads use those classes as non thread autonomous classes.
Java Code:
public class Aclass {
private static Thread t[];
public static void main(String[] args) throws IOException {
for (int Game = 0; Game< 10; Game++) {
t[Game] = new Thread(new thePackage2.RunTheGame(aplayer, bplayer, Name, ID , Pmach));
t[Game].start();
[Code] .....
I have a 2x2 matrix and a 2 dimensional array.Let's say, my matrix is [a b] and array is [[1, 2], [3, 4], [5, 6],[23, 11]] .I need to multiply each 1 dimensional array in above array with the matrix.For instance,
[1, 2] multiply with [a b]
[3, 4] multiply with [a b]
[5, 6] multiply with [a b]
[23, 11] multiply with [a b]
So, each 1 dimensional array in there will be multiplied with matrix [a b] (same with matrix multiplication).how to do that multiplication in java. But I confuse how to 'release' each 1 dimensional array from the first array so I can do multiplication.How to do that in java?
Java Code:
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class Screen implements ActionListener {
public JButton[][] b=new JButton[200][200];
[Code] ....
I am trying to create the A* Algorithm and I REALLY need a 2D array to handle this.
This is the error:
Java Code:
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162) mh_sh_highlight_all('java');
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
[Code]....
I am trying to program an A* algorithm and I cannot even get past the buttons. I need a 2D array of buttons to handle this problem but I am getting the following errors.
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
[Code] ....
Whilst pre-preparing for java certification, one of the online mock exams has slightly confused me by saying my answer was incorrect for multi-dimension array 'declaration and instantiation'.
This is one of the answers i chose - which was marked as incorrect
a)
int[][] array2d = {{123}, {4,5}};
Which looks absolutely fine to me.One of the other answers, which i agree is correct and so does the mock exam is
b)
int [][] array2d = new int[2][2];
I need to write a method that accepts an array of ints and squares each element of the array. No creating new arrays and no returning any values.
public void squareInts(int[] ints) {
for(int i = 0; i < ints.length; i++) {
ints[i] = (ints[i] * ints[i]);
}
}
How to declare a 2 dimensional array of interger of size 10 by 10. and then set every element of the array to 3. After this I need to add up all the element in this array and return the value.
final int ROWS = 10;
final int COLS = 10;
int[][] foo = new int[ROWS][COLS];
for (int i = 0; i < ROWS; i++){
for(int j = 0; i< COLS; i++){
foo[i][j] = 3;
}
}
This is what i have done so far(not 100% if is correct..) but how to add up all the array.
I am working on the following java assignment..Write a program that randomly fills in 0s and 1s into a 4- by- 4 matrix, prints the matrix, and finds the first row and column with the most 1s. Here is a sample run of the program:
0011
0011
1101
1010
The largest row index: 2
The largest column index: 2
I have code that generates random 0s and 1s for the array, how to get the largest column and row.
import java.util.Random;
public class LargestRowColumn {
public static void main(String[] args){
//create 4x4 array matrix
int arrayMatrix[][] = new int[4][4];
[code]....
finding the row and column with the largest amount of 1s. I keep thinking well if I scan and find a one in the array, maybe I can just save the index of the row and column and then determine which index contains the most 1's after the array has been scanned.
I am workinh with a couple of functions that deal with two dimensional (square) arrays of integers, doing things like checking equality, etc. For example, I know that I get an ArrayOutOfBoundsException in the isEqual function, but I don't know why.
public class MatrixUtils {
//This function checks if two matrices are equal
public static boolean isEqual(int A[][], int B[][]) {
for(int i=0; i<A.length; i++) {
for(int j=0; j<A.length; i++) {
if (A[i][j] != B[i][j]) return false;
[Code] ....
I have to make a program in which users inputs a number and the program should search into a two dimensional array and print out all the values that are below the number This is my first time experimenting with 2D Arrays and how to do this program I have the array set up
String firstarray[][]=
{{"", "Store101", "Store102", "Store103", "Store104"},
{"Tennis Shoes", "102", "54", "20", "78"},
{"Sweaters", "45", "25", "35", "75"},
{"Jeans", "12", "35", "45", "65"},
{"Shorts", "54", "25", "34", "45"},
{"Jackets", "15", "35", "50", "25"}
};
Is it possible to have a two dimensional array that has a string and an int, so like combining these into a two dimensional instead of one:
String [] w = {"help", "me"}; and int [] n = {4,2};
obviously not what I'm really working on, but u should get the point.
I am having trouble fixing and figuring out how to change my code. My out put is very off.
"
Enter a 3-by-3 matrix row by row:
1 1 1
1 1 1
1 1 1
Sum of the major diagonal is 6.0
Sum of the values of the column are: 10.0
Sum of the values of the column are: 20.0
Sum of the values of the column are: 30.0 "
Code is below:
public static void main(String[] args) {
double[][] m = new double[3][3];
m = createArray();
}
private static double[][] createArray() {
[Code] ....
I want to compere two element of string array by each other! eventually I want to print Yes or No in matrix . SO, I start reading data from file then split them into two parts .
File file= new File(fileName);
try {
inputStream = new Scanner(file);
while (inputStream.hasNext()){
String data= inputStream.next();
String [] token =data.split(",");
System.out.println("day"+token[0] +"embloyee name:"+ token[1]) ;
}
inputStream.close();
Now I want to compere each cell from token[0] by another array :
String[] day= { "Sunday", "Monday" ................};
if the days are equal then I want print yes in front of the employee name if not then i want to print No..is this gone work with me as I imagine it to be or do I have to take few more steps to get my code going?
I want to declare a 2 dimensional array in java which has 3 column and unlimited number of rows, i want to give a special name to each column . The type of first column is string second one is int and the last one is string
Column1_name
Column2_name
Column3_name
String value
Int value
String value
.
.
.
.
.
.
I have a boolean array that looks like this
boolean seat[][] = new boolean[2][3];
I reserved one row for first class and another for economy class. This code works just as I want but my question is how can I loop through it so I don't need all the if statements? I tried it many ways. I tried something like this but I cant get it to work.
for (int row=0;row<seat.length;row++{
for (int col=0;col<seat[row].length;col++){
if (seat[0][col]==false){
seat[0][col]=true;
System.out.println("You have number 0" + row + in first class);
[Code] ......
I need to design a class named Location for locating a maximal value and its location in a two-dimensional array. The class should contain public data fields row, column, and maxValue that store the maximal value and its indices in a two dimensional array with row and column as int type and maxValue as double type.
I need to write the following method that returns the location of the largest element in a two-dimensional array:
public static location locateLargest(double[][] a)
The return value is an instance of Location. Write a test program that prompts the user to enter a two-dimensional array and displays the location of the largest element in the array.
Here is what i get when I run
Enter the number of rows and columns of the array:
3 4
Enter the array: 23.5 35 2 10
4.5 3 45 3.5
35 44 5.5 9.6
The location of the largest element is at 00
The location of the largest element is at 01
But I need it to display this instead.
Enter the number of rows and columns of the array:
3 4
Enter the array: 23.5 35 2 10
4.5 3 45 3.5
35 44 5.5 9.6
The location of the largest element is 45 at (1,2)
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Number of rows and columns: ");
int row = input.nextInt();
int col = input.nextInt();
[Code] ....
Enter the number of rows and columns of the array:
3 4
Enter the array: 23.5 35 2 10
4.5 3 45 3.5
35 44 5.5 9.6
The location of the largest element is at 00
The location of the largest element is at 01
I need it to display this instead.
Enter the number of rows and columns of the array:
3 4
Enter the array: 23.5 35 2 10
4.5 3 45 3.5
35 44 5.5 9.6
The location of the largest element is 45 at (1,2)
I have been working on this assignment for a bit now. I seem to have most of the logic of it down, as far as I can tell, but I seem to have fallen into a bit of a brain lapse when it comes to invoking methods I've made in my main method. Here's the code:
package Module5;
import java.util.Scanner;
public class Exercise6Nine {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter 10 numbers.");
double[] numbers = new double[10];
[Code] .....
My question is, in my main method, I have code in there to attempt to call my method "min" from below, and to use the result of the min's calculations and print them via my main. Only, I can't seem to properly invoke the method from my main method!
Also, if you could check over my min method and see if anything blatantly wrong is there and let me know, that would be great.
Looking over my question, and it seems there is no EDIT button, but I may as well put the assignment parameters here, since I asked for double checking on my method. Write a method that finds the smallest element in an array of double values using the following header:
public static double min( double[ ] array )
Write a test program that prompts the user to enter 10 numbers, invokes this method to return the minimum value, and displays the minimum value.
What the program must do is to parse the string-declared two-dimensional array for the program to compute the student's scores in their quizzes, but I'm having difficulty in anything with Parsing so I don't know what will be the appropriate codes.
Error: incompatible types: String[][] cannot be converted to int[][]
import java.io.*;
public class Quiz3{
public static void main(String[]args)throws IOException{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String [][]StudQuiz = new String [5][4];
[Code] ....
How am I able to compute the average of the score if the data that is needed to be computed is in the string-declared array?
I am pretty new to Java and am just learning about two dimensional arrays. I think that I understand the concept, but I seem to be having trouble adding stuff to my array. I wanted to make an array to hold both strings and integers, but wasn't sure if I could put integers in a string array. So I thought that I would be able to convert my integers to string and then add them. This however causes an error. This is my code(yes its probably not the best):
static String [][] students = new String [14][4];
static int number = 0;
String fName, lName, fullName;
int test1, test2, test3, test4;
String a, b, c, d;
[Code] .....
Long story short: The program takes user values (temperature) and converts them to the opposite (C >> F / F >> C)
I originally started this program with three separate arrays but then decided that it would be a good opportunity to use a two-dimensional array and one other.
The two-dimensional array has 2 rows, 10 columns. The second is a normal String array ...
Java Code:
String[][] myTemperatures = new String[2][9];
String inputAssembly[] = new String[9]; mh_sh_highlight_all('java');
I prompt the user for to enter temperature values, using a GUI and jbutton to distinguish F/C. Each time the user clicks 'continue', the values are stored into the two-dimensional array. One row holds the temperature, the other holds the C or F designation.
Java Code:
// CONTINUE BUTTON CLICK ACTIONS
class ContinueButtonListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
input = view.getTempValue();
[Code] ....
This is where I am experiencing the trouble and I cannot seem to get the Debug to work properly here. When the two-dimensional array is full OR the user clicks 'calculate' instead of 'continue', the Calculate event is performed via an ActionListener.
Java Code:
// CALCULATE BUTTON CLICK ACTIONS
class CalculateButtonListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
String hold;
Double temp;
And I get a ton of errrors ...
Java Code:
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "[Ljava.lang.String;@7441b1fd"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
[Code] ....
I imagine the issue lies within how I am handling the two-dimensional array in the CALCULATE event and/or converting the String[][] to String then parsing to an Integer.
Would this be better done is separate arrays (not using one two-dimensional, but storing 34C, 45F ... in one. I think this would be difficult for me to parse for conversions).
Java Code:
// Demonstrate a two-dimensional array
class TwoDArray {
public static void main(String args[]) {
int twoD[] [] = new int[4] [5];
int i, j, k = 0;
[Code] .....
Output:
0 1 2 3 4
5 6 7 8 9
10 11 12 13 14
15 16 17 18 19
(1) I don't understand how repeating the loop creates the structure of the output. Taking the second loop away and putting the "System.out.print(twoD[i] [j] + " " );" under k++ creates the output to print a number on each line. How do I write the code not having the second loop, assigning k to each value that is moved through the grid then printing it out but having the output the same?
Java Code:
for(i=0; i<4; i++)
for(j=0; j<5; j++) {
twoD[i][j] = k;
k++;
System.out.print(twoD[i] [j] + " " );
System.out.println();
} mh_sh_highlight_all('java');
(2) I don't understand why you can't put a new line sandwiched between the first for loop
Java Code:
for(i=0; i<4; i++)
System.out.println();
for(j=0; j<5; j++) {
twoD[i][j] = k;
k++; mh_sh_highlight_all('java');
It compiles, but I get the message:
" Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4
at TwoDArray.main(TwoDArray.java:11) "
Suppose I have private static void name() { ... } that has a two dimensional string array named array[. Now suppose I have private static void different() {...} and I want to write a condition where if (item == array) { ... }, how can I access my array from name() when I am in different()? I get a compile error saying cannot find symbol. My code is similar to:
Java Code:
public static void main(String[] args) {
...
String item = keyboard.nextLine();
... }
private static void name() {
...
String[][] array = new String[1][5];
[Code] .....