Matrix addition and subtraction in java

by August 4, 2017 Java programs

Let’s learn matrix addition and subtraction in java.

Matrix addition and subtraction in java

A matrix represents a two-dimensional array. Here user enters the number of rows and columns.

Nested for loop is used to read the input. Outer for loop “m” ranges from 0 to number of rows of the matrix.

Meanwhile inner for loop “n” ranges from 0 to number of columns of matrix.

The input is read using nextInt() method of class Scanner and stored in x[m][n] and y[m][n] position.

After reading elements, two for loops is used to add two matrices with loop index. Then finally result is stored in z[m][n] array.

Here’s matrix addition in java and sum of matrix elements in java.

// matrix addition java
import java.util.Scanner;
public class MatrixAdditionDemo
{
   public static void main(String[] args)
   {
      Scanner sc = new Scanner(System.in);
      System.out.println("Please enter number of rows : ");
      int row = sc.nextInt();
      System.out.println("Please enter number of columns : ");
      int col = sc.nextInt();
      int[][] x = new int[row][col];
      int[][] y = new int[row][col];
      System.out.println("Please enter first matrix - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            x[m][n] = sc.nextInt();
         }
      }
      System.out.println("Please enter second matrix - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            y[m][n] = sc.nextInt();
         }
      }
      // matrix java
      int[][] z = new int[row][col];
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            // matrix addition in java
            z[m][n] = x[m][n] + y[m][n];
         }
      }
      System.out.println("The addition of two matrices is - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            System.out.print(z[m][n] + " ");
         }
         System.out.println();
      }
      sc.close();
   }
}

Output:

matrix addition and subtraction in java

Similar to matrix addition in java we can write java program to subtract two matrices.

// matrix subtraction in java
import java.util.Scanner;
public class MatrixSubtractionDemo
{
   public static void main(String[] args)
   {
      Scanner sc = new Scanner(System.in);
      System.out.println("Please enter number of rows : ");
      int row = sc.nextInt();
      System.out.println("Please enter number of columns : ");
      int col = sc.nextInt();
      int[][] x = new int[row][col];
      int[][] y = new int[row][col];
      System.out.println("Please enter first matrix - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            x[m][n] = sc.nextInt();
         }
      }
      System.out.println("Please enter second matrix - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            y[m][n] = sc.nextInt();
         }
      }
      int[][] z = new int[row][col];
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            // subtraction java
            z[m][n] = x[m][n] - y[m][n];
         }
      }
      System.out.println("The subtraction of two matrices is - ");
      for(int m = 0; m < row; m++)
      {
         for(int n = 0; n < col; n++)
         {
            System.out.print(z[m][n] + " ");
         }
         System.out.println();
      }
      sc.close();
   }
}

Output:

matrix addition and subtraction in java

Also read – variables in java