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 RepliesI am having trouble grasping 2 dimensional arrays .I have a certain problem:
String[][] words = {
{"Red", "Blue", "Green"},
{"Orange", "Purple". "Yellow"}
[code]....
I ran the code and got OrangePurpleYellowRedBlueGreen.
I have the program bellow that grades students(based on a two dimensional array with the answers) and i need to make it display the students based on the grades/scores in ascending order . I did that in two ways (using a array and a two dimensional array) but i have a hunch it can be done much more simple then i did it (but still using array object and nothing else ) .
public class GradeExam {
/** Main method */
public static void main(String args[]) {
// Students' answers to the questions
char[][] answers = {
[code]....
My first solution creating an array with the grades for sorting :
public class C8_3 {
public static void main(String args[]) {
// Students' answers to the questions
char[][] answers = {
{'A', 'B', 'A', 'C', 'C', 'D', 'E', 'E', 'A', 'D'},
{'D', 'B', 'A', 'B', 'C', 'A', 'E', 'E', 'A', 'D'},
[code]....
I need to write a class that represents and image of RGB pixels. This class uses a two-dimensional array of object type that represents R,G and B values.
When I compile the class it completes successfully. However, when I try running a "tester" class , I'm encountering errors in a few methods. I've been trying it out for 2 days now, but unsuccessfully thus far..Those method are : rotating the image by 90 degrees clockwise (and vice versa , but I just use clockwise method 3 times for that) , shifting the image sideways, and shifting the image up/down..
I've attached the whole source code for the class , and the list of errors I get when I try to run my tester. URL...
I am having problems figuring out how to make calculations using a two dimensional array. The problem is finding the distance of a projectile given the launch velocity and angle. The equation is x = v^2*sin(2theta)/g. I understand how to implement this equation using the toRadians() and Sin() methods. What I don't understand is how to calculate the distance values with a multi dimensional array.
double [][] data = { {20, 15},
{50, 35},
{80, 45},
{100, 65},
{150, 85},
{10, 50},
{110, 8}};
My array has the velocities on the left and angles on the right. I tried using nested loops but I don't know how to access the two pieces of data at a time which I need.
The international Olympics Committee has asked you to write a program to process the data and determine the medal winners for the pairs figure skating. You will be given the following file: Pairs.txt
Which contains the data for each pair of skaters. The data consists of each skater's name, their country and the score from each of eight judges on the technical aspects and on the performance aspects. A typical record would be as follows:
Smith
Jones
Australia
5.0 4.9 5.1 5.2 5.0 5.1 5.2 4.8
4.3 4.7 4.8 4.9 4.6 4.8 4.9 4.5
The final score for each skater is the sum of the average of the two categories of score. Design a class to hold the above data and the final score. Read the data in from the file and calculate the final score for each pair. Sort the array of objects , and display the results on the screen in order, giving special prominence to the medal winners.
Here is my CLass:
public class Skaters {
private String name1;
private String name2;
private String country;
private double [] arrTech = new double [8];
private double [] arrArt = new double [8];
private double score;
[code]...
how do i print my 2 arrays using the file? i got the name1, name2 and counntry to print but im stuck on printing the scores that are stored in the arrays. Also, i have to print the average for each array. one is for techniques and the other one is artistic. as you can see i already wrote the code for it but im stuck in printing it.
I am trying to create a program for class the uses two dimensional arrays. I am stuck on the second step that states Use two parallel arrays. One is a two-dimensional array -- a row of this array will hold six values in this order: [0] number of hours worked, [1] hourly pay rate, [2] gross pay, [3] net pay, [4] federal withholding, and [5] state withholding.
This is what I have so far:
Java Code:
double [][] data = new double [30][6];
String [] names = new String [30];
String str = null;
String detail = null;
int n = input(data, names, inputFile); mh_sh_highlight_all('java');
(there's more but i don't believe it pertains to this question)
My question is how would I create this array. Or, is that right above? I've searched online and in my book and I just don't understand.
Recently I have missed a few weeks of my class due to family emergencies. Because of this I have missed very important lectures. My professor has assigned me the following assignment:
Prices Write a Java program that specifies three one-dimensional arrays names price, amount, and total. Each array should be capable of holding 10 elements. Using a loop, input values for the price and amount arrays. The entries in the total array should be the product of the corresponding values in the price and amount arrays. After all the data have been entered, display the following output:
Total Price Amount
==== ==== ======
Under each column heading display the appropriate value.
I know how to display everything using printf, how to create the actual arrays and define the array size, but I am confused on how and what loop to use and how to construct it. This is what I have managed to write up so far:
import java.util.Scanner; // Imports the Scanner class
import java.text.DecimalFormat; // Imports the DecimalFormat class
public class Prices
{
public static void main(String [] args)
{
double[] price = new double[10];
double[] amount = new double[10];
double[] total = new double[10];
// Create a new Scanner object
Scanner keyboard = new Scanner(System.in);
} //End of main method
} // End of public class
As part of the instructions we are required to use loops and methods to solve to program this code. We are not allowed to use any set functions that are already built in java.The methods for intersection and difference MUST return int value.
import java.util.Scanner;
public class setPractice {
public static Scanner kbd;
public static final int MAXSIZE = 20;
public static void main(String[] args) {
kbd = new Scanner(System.in);
[code]...
Im trying to make a tic tac toe game that you play against the computer using a random number generator and two dimensional arrays for the game board. Im not trying to make a GUI, the assignment is to have the board in the console, which I have done. I have run into a few problems with trying to get the computer player to correctly generate 2 integers and have those two integers be a place on the game board. Here is my code so far.
import java.util.Random;
import java.util.Scanner;
public class TicTacToe {
private static Scanner keyboard = new Scanner(System.in);
private static char[][] board = new char[3][3];
public static int row, col;
[Code] ....
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'm wonder about the issue of constructor for arrays. Let say I have a class tablica, and one component int[] tab. If I get it right until now tab is nothing more than empty reference to some unexisting array?
import java.util.Random;
class tablica{
int[] tab;
tablica (){ // i wish it was constructor
[code]....
Then, I'm trying to build the constructor for class tablica. What can be the parameter of such constructor? Is it fields of array? It is simple forf for basic variable
- I liken values defined in constructor with those global defined in class. But how to do it with array component tab.
If I create array object in main method then how can I use this constructor?
How do i increase the size of a 2D array from 2X2 to 4X4 where only the boundary elements are zeroes and the rest of them remain the same?
View Replies View RelatedIn the program below I populated three arrays: student id, name, and GPA. The findStudent() method attempts to match users input with the input stored in the studentID array using an if/ else statement. When I use the if/ else statement the else always executes regardless if the IDs match? I am trying to get JOptionPane.showMessageDialog(null, "Incorrect entry"); to print only if the IDs don't match.
Java Code:
//FILE: StudentIDArray.java
import javax.swing.*; //Used for the JOption dialog boxes
import java.util.*; //Used for Scanner input
public class StudentIDArray {
boolean nameFound = true;
final int numOfElements = 2; //Final int to control to loop for data
[code]....
I'm working on a side project, which will eventually hopefully be a Pokedex, and I've just been going to it at the end of every chapter and using the stuff I've learned to work on it.So I just read chapter 3, which is all about variables and teaches how to use arrays.
my question is, does an array have to be declared inside a method? Because I'm trying to create an array inside a class without any methods and without the main, and I continuously get errors. Here's a quick working of my code that won't compile.
class blah {
blah a[] = new blah[7];
a[0] = new blah();
}
The error message focuses on a[0] = new blah(); Telling me the 0 should be a ], the = is an illegal start of type, so on and so forth. The program compiles completely fine if it's within a method, like this:
class blah {
void a() {
blah a[] = new blah[7];
a[0] = new blah();
}
}
Or if I have public static void main (String[]args); But I'm trying to practice working outside of main.So does an array have to be within a method,
I have created a class and a matrix of doubles (or at least, I think I have, that's partly what I want to verify).I need to return the values of the array,Here is my class:
public class example{
double[][] Position=new double[2][11];
double calculate(){
for (int time=0;time<=10;time=time+1){
Position[1][time]=time;
Position[2][time]=time+1;
double A=Position[2][time];
return A;
}
}
}
I am getting the error: "This method must return a result of type double", though to me it looks like I am returning double (A).
I am having trouble conceptualizing how to fill arrays. I understand that I can declare one and number it's elements, and it stores values of a certain data types. I don't really understand beyond that. Like how I would fill and use data in it.
I can be more specific with an assignment I have for school, but need to get started understanding how to fill arrays with data and then how to use that data.
So im making this ghost game where i display an 8x8 filled with 0s and a randomly generator five 1s in there I can get it to display 0s and add 1s, however sometimes the 1s that are randomly generated sometimes go on the same spot making it look like there are only four 1s. How would i go about fixing that?
package Grade12;
import java.util.Random;
public class Ghost {
public static void main(String[] args) {
Random generator = new Random();
int gameboard [][] = new int [8][8];
int randomx, randomy, counter = 0, sum = 0;
for(int row = 0; row < 8; row++){
for(int col = 0; col < 8; col++){
(gameboard[row][col]) = 0;
}
[code]...
The assignment goes like this...Write a Payroll class that uses the following arrays as fields:
employeeID - An array of seven integers to hold employee identification numbers. The array should be initialized with the following numbers:
5658845452012578951228777541
845127713028507580489
hours - An array of seven integers to hold the number of hours worked by each employee.payRate - An array of seven doubles to hold each employee's hourly pay rate.wages - An array of seven doubles to hold each employee's gross wages.The class should relate the data in each array through the subscripts.
For example, the number in element 0 of the hours array should be the number of hours worked by the employee whose identification number is stored in element 0 of the employeeID array. That same employee's pay rate should be stored in element 0 of the payRate array. In addition to the appropriate accessor and mutator methods, the class should have a method that accepts an employee's identification number as an argument and returns the gross pay for that employee.Demonstrate the class in a complete program that displays each employee number and asks the user to enter that employee's hours and pay rate. It should then display each employee's identification number and gross wages.Input Validation: Do not accept negative values for hours or numbers less than 6.0 for a pay rate.
My problem with this program is that everytime I try to print the employee ID's or the wages, I get hashcode or something like it (#[I1a77cdc or something like that). I tried using the toString method, but it lists all of the values, when I'm trying to display one at a time. Here is the code for the class:
// moduleArray class
public class moduleArray {
final int NUM_EMPLOYEES = 7;
int[] employeeID = {5658845, 4520125, 7895122, 8777541, 8451277, 1302850, 7580489};
int[] hours = new int[NUM_EMPLOYEES];
[code]...
This is the demo program to list the ID's. I've been messing with it for some time, and right now I just want it to display values.
import java.util.Scanner;
public class moduleArrayDemo {
public static void main(String[] args) {
final int NUM_EMPLOYEES = 7;
int[] ID = new int[NUM_EMPLOYEES];
[code]...
Okay, so the assignment was creating a word search for the given array. I've created all the code necessary, but I've ran into trouble. This problem occurs with the Up-Forward, Up-Backward, Down-Forward, and Down-Backward sections. If I only set one of these to run, it works. But if I have all 4 set at the same time, it errors out on the first one that runs.
public class P_WordSearch {
public static void main(String[] args) {
char[][] puzzle = {
{'B','O','O','G','S','R','O','W','I','N','G'},
{'E','B','L','G','N','I','M','M','I','W','S'},
{'L','C','E','A','T','I','P','U','P','I','S'},
{'C','M','I','N','C','A','X','Y','O','S','N'},
[Code] ....
I am trying to concatenate two arrays but on on compiling it is showing
Java Code: import static java.util.Arrays.*;
class Mergesort
{
public static void main(String...s)
{
Mergesort r=new Mergesort();
int x[]={1,2,3,4,5,6};
int y[]={9,8,7,15,14,13,12,11};
[Code]...
I am receiving one error when using arrays and methods. It's at the bottom of the code and I have commented what the error is .
import java.io.*;
import javax.swing.*;
public class CEO_PROGRAM_PartB
{
public static void main (String[] args) throws IOException
[code]....
The assignment was to create 3 parallel arrays to make a student database.The first array will contain 4 digit student id's, the second a string array with student names, and the third array is student gpa's. The user is to receive a dialog box asking to enter the student id, and if the id is correct the user is to see the student name and grade. If the user input does not match any value in the student id array, the user is to receive a message stating invalid id. Here is the code I have so far.
For some reason no matter what the user enters, the information for the last array entry is displayed.
public class parallelStudent
{
public static int sequentialSearch(int[] array, int value)
{
int index; //loop control variable
int element; //element the value is found at
boolean found; //flag indicating search results
[code]...
We had to use these methods with the given parameters and code them correctly. We cannot use any built in java methods for sets.
import java.util.Scanner;
public class setPractice {
public static Scanner kbd;
public static final int MAXSIZE = 20;
public static void main(String[] args) {
kbd = new Scanner(System.in);
int[] setA = new int[MAXSIZE];
int[] setB = new int[MAXSIZE];
int[] intersect = new int[MAXSIZE];
[Code] ....
This is the input given to the program:
How many numbers will be in the 1st set: 3 Enter list of integers for 1st set: 12 3 2
The ascending order for 1st is: 2 3 12
How many numbers will be in the 2nd set: 4
Enter list of integers for 2nd set: 2 3 6 1
The ascending order for the 2nd set is: 1 2 3 6
The intersection of the two sets is: 0 0 0 //Program not correctly print intersection of two sets
The difference of A-B is: //Program is not printing the difference either...
import java.util.*;
public class OneDimenArray {
public static void main(String[] args) {
double[] decimals = new double[12];
double nums = 0.0;
double a = 1.0;
[Code] ....
These are the erroe codes I'm getting;
OneDimenArray.java:13: error: ']' expected
double[] decimals = double[Scanner.nextDouble()];
^
OneDimenArray.java:13: error: ';' expected
double[] decimals = double[Scanner.nextDouble()];
^
2 errors
----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.
I need to send a byte array across a network. I know how to do this. (server->client)
byte[] myArray = new byte[]{0,1,2,3,4,5,6,7,8,9};
DataOutputStream.write(myArray);
... and I know how to receive it.
byte[] myArray = new byte[10];
DataInputStream.read(myArray);
When I send over one of these arrays, it ends up stopping storing values in the array when only about half the array is received, even though the array is sent from the server all at once. This results in the receiver's array, in this case, being something like {1,2,3,4,0,0,0,0,0,0}.
I can easily solve this - and already have - by simply adding a loop onto it and waiting for the bytes to all be received, as the method returns the amount of bytes actually read.
byte[] myArray = new byte[10];
int bytesRead = 0;
while( bytesRead < myArray.length) {
bytesRead += DataInputStream.read( myArray, bytesRead, myArray.length - bytesRead );
}
I am simply wondering if there is a better solution to this, as the current solution isn't that elegant. Did I do something wrong to cause only a part of the array to be sent first? Would it be better to use DataInputStream.readByte() to read off the bytes one by one rather than an array at once, and then store them in an array afterward? Would this cause a performance decrease as each byte is read individually? (I'm sending an array of several million bytes)