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
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1.How to declare array in java?
2.How to push elements in it in key-value value pair in java?
For example-
This is the way i do it in javascript..
I want to do like this in java..
var my_array;
for(var i = 0; i<5; i++)
{
my_array.push({x: i, y:0});
}
where,push is builtin method in javascript.
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?
I have a jtable which i want to put an array into... and Really don't know how.. I dont want to use array list mainly because it looks way to complicated so there must be some other way using defaultablemodel but i dont know how..
So here's my code: just a snippet which includes the testing of the jtable
String[] columns = {"col1", "col2", "col3", "col4", "col5", "col6"};
//declare 2d array
String[] [] data = {{"1", "2", "3", "4", "5", "6"}};
jt = new JTable (data, columns);
jt.setPreferredScrollableViewportSize (new Dimension (50, 80));
//set initial selectibility to false
jt.setFocusable (false);
jt.setRowSelectionAllowed (false);
JScrollPane tableContainer = new JScrollPane (jt);
frame.getContentPane ().add (tableContainer);
Still trying to get a handle on arrays! So, I declare an array to be a 46x1 and I am trying to populate it with a Log formula that I am using but I keep getting an ArrayIndexOutofBoundsException.
Code :
private double[][] LNValues = new double[46][1];
//Calculating y=LN(E-k) and Initializing the Array
for(int x=0; x<LNValues.length; x++)
{
double i = Math.log(eValues[x][1] - kValue);
if(i > 0)
[Code] ....
The main Method
-Create a main method declares and creates an integer array called nums that can hold 15 integers.
-Use a for loop to fill that array with multiples of 3: 0, 3, 6, 9, etc.
-Then use similar for loop to print each value in the array on one line, with each value separated by a single space.
-Compile and run the program to see the result:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
As you write other methods, you'll also modify the main method to make calls to them. The printArray MethodWrite a method called printArray that accepts an integer array as a parameter. This method does not return a value, and must be declared as static so that the main method can call it. Instead of printing the array in the main method, move that loop into this method. Call the printArray method from the main method. Compile and run the program to verify it prints the sam result as before.Add a println statement so that after printing the array values on one line, it then moves to the following line.Finally, modify the loop in the printArray method so that, instead of using a traditional for loop, it instead uses a for-each loop. Compile and run the program again.
Part III: More Array Methods
The linearSearch Method In lecture we looked at a method that performed a binary search on a sorted array. A much simpler (though much less efficient) search is a linear search, that simply starts at the front of the array and looks at each element in turn until it finds it or reaches the end.Create a method called linearSearch that accepts an integer array and a single int value as parameters. The goal of the method is to find the second parameter (the target) in the array. The method should return a single int representing the index of the target value. This method should not print any output itself. In this method, use a traditional for loop to scan through the elements in the array. As soon as you find the target value, return the index of that value.
If you scan through the entire array without finding the target value, return a -1.Modify the main method to call the linearSearch method and print the results. Call it twice, searching for the value 18 (which it should find) and the value 10 (which it should not). Including the previous activity, the output of the main method should now look similar to this:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sumArray Method
The sumArray method should take an integer array as a parameter and return a single integer representing the sum of all values in that array.Use a for-each loop to access each value in the array and compute a running sum. After the loop, return the total.Call the method from the main method, producing the following augmented output:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sum of this array is 315
The addValue Method...The addValue method should accept an integer array and a single int as parameters. The purpose of the method is to add the second parameter to EACH value in the array. The addValue method does not return a value, but the elements inside the array will be modified. Call the addValue method from the main method, adding 100 to each element in the array. Then call the printArray method again to see the modified array values:0 3 6 9 12 15 18 21 24 27 30 33 36 39 42
The index of 18 is 6
The index of 10 is -1
The sum of this array is 315 100 103 106 109 112 115 118 121 124 127 130 133 136 139 142
Test a Different Array..Finally, duplicate the content of the main method to perform similar tests on another array. Instead of filling it with multiples of 3, fill it with multiples of 4. And instead of using an array size of 15, use an array size of 20.Modify the values search for to include one that is in the array and one that isn't.Rerun the main method and carefully check the results.If you haven't been doing it all along (which you should), make sure the appropriate class and method documentation is included.When you're satisfied that all methods are working correctly, modify the main method to delete the second array tests.
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 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 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]....
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] .....
I have a question about an error I am getting when trying to pass a two dimensional array to a method. I keep getting the "incompatible types, int cannot be converted to int[][]". I am getting the error in a few different place (see comments - at the first call of the method, at a recursive call, and at the return statement. I believe I am passing the same type of array in all cases to the type of array defined in the method parameters.
Below is my code.
// this is a call from the main method
int[][] c = new int[temp1.length][temp1.length];
c = MatrixMultiply(a,b); // this is first place the error occurs
} // end main
public static int MatrixMultiply(int[][] A, int[][] B) {
// throw new UnsupportedOperationException("Not supported yet.");
int a[][] = A;
[Code]....
I have several private jars which are linked to my project and I need them to write and read values tofrom the same b-dimensional array. Actually I need a single array which in which my app and its linked jars will write to and read from it. How can I achieve that?
View Replies View RelatedI have this 2 dimensional array that represents color pixels
RGBColor[][] rgbArray1 = new RGBColor[rows][columns] - so each elemnt in this array is a pixel - (red, green, blue)
I wrote a class named RGBImage. represents an image. the constructor of this class takes RGBColor[][] rgbArray1 as an argument and print the image.
My problem is when i try to rotate the image 90 degrees. because the dimentions are changeing. i'm getting ArrayIndexOutOfBounce Exception.
I know i can to this by create a bigger 2 dimensional array and copy the original , but for this assignment i cant do this .
I must use the original one . now i will show the main method that will get things clearer if i didnt explained well enough.
System.out.println("Constructor with RGBColor[][] Array Parameter:");
RGBColor[][] rgbArray1 = new RGBColor[3][4];
for (int i=0; i<rgbArray1.length;i++)
for (int j=0; j<rgbArray1[0].length;j++)
rgbArray1[i][j] = new RGBColor(i,i,i);
[Code] ....
output:
(0,0,0) (0,0,0) (0,0,0) (0,0,0)
(1,1,1) (1,1,1) (1,1,1) (1,1,1)
(2,2,2) (2,2,2) (2,2,2) (2,2,2)
(2,2,2) (1,1,1) (0,0,0)
(2,2,2) (1,1,1) (0,0,0)
(2,2,2) (1,1,1) (0,0,0)
(2,2,2) (1,1,1) (0,0,0)
This outputs are what i need to accomplish.
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?
So I am trying to open a file and store the contents into a two dimensional array. I seem to have no problem using this same basic code to read the file and output it. But when I try to change it so that all the data is stored into the array, it does not work.
Java Code:
public void convertFile()
{
String filePath = ("C:UsersBradDownloadsFB1.csv");
String [][] rowCol = new String [429][6];
try
{
BufferedReader br = new BufferedReader(new FileReader(filePath));
StringTokenizer st = null;
System.out.println("Your file is being converted to an array. This may take several minutes.");
[code]....