Addition of array elements in Java.

Question

Hi!

I need help in a program. It has 2 2*2 array. The program asks to input their value and then adds the two matrix elements to the other. Program should looks like this.
Please give the first matrix elements:
1 2
3 4
Please give the second matrix elements:
5 -1
3 -4
The result:
6 1
6 0

Also the result must not contain whitespace at the end of the line.
The numbers are integers.
int [][] firstMatrix = new int [1][1];
int [][] secondMatrix = new int [1][1];
This code is good to create the 2*2 array? How to input their values by user?
Thanks in advance!

Answer 1

Hello, one way to prompt the user to input values in your code is by importing and getting a Scanner like so:
import java.util.Scanner;

//Get a new Scanner next:
Scanner test = new Scanner(System.in);

//Save/ask for input:
String word = test.next();

//If it's a number:
int number = test.nextInt();

Note: since you want to fill up a matrix by multiple inputs from the user, it may be an option to create several 'for' loops (even nested). In pseudo-code:
For i=0 until you reach the length of the array, ask for user input.

Sorry for the long post, hope that helps and good luck!

Answer 2

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int [][] firstMatrix = new int [2][2];
int [][] secondMatrix = new int [2][2];
System.out.println("Please give the first matrix elements:");
for (int i= 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
int number = sc.nextInt();
firstMatrix [i][j] = number;
}
}
System.out.println("Please give the second matrix elements:");
for (int i= 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
int number = sc.nextInt();
secondMatrix [i][j] = number;
}
}
System.out.println("The result:");
System.out.print((firstMatrix[0][0] + secondMatrix[0][0]) + " " + (firstMatrix[0][1] + secondMatrix[0][1]));
System.out.println();
System.out.print((firstMatrix[1][0] + secondMatrix[1][0]) + " " + (firstMatrix[1][1] + secondMatrix[1][1]));
}
}

Working perfectly, thanks for help!