Write a Java program to Add Two Matrices

Problem Description

In this post, we will write a sample java program to add two matrices. We would prompt the matrix dimensions and the matrix elements from the user. We will calculate the matrix sum as a third matrix and display the output in the console window. At the end of the post, we will display a sample output of the program.

Java Program

package matrix;

import java.util.Scanner;
// Demo program to add two matrices 
// www.TestingDocs.com
public class AddMatrixDemo {

  public static void main(String args[]) {

    Scanner in = new Scanner(System.in);
    System.out.println("Please enter the number of Rows and Columns of Matrix:= ");

    //intialise rows of matrix as m
    int m = in.nextInt();

    //intialise columns of matrix as n
    int n = in.nextInt();

    //intialise the first matrix with m as rows and n as columns
    int firstMatrix[][] = new int[m][n];

    //intialise the second matrix with m as rows and n as columns
    int secondMatrix[][] = new int[m][n];

    //intialise the sum of two matrices with m as rows and n as columns
    int sumOfMatrix[][] = new int[m][n];

    System.out.println("Enter the elements of First Matrix:= ");
    for (int i=0;i<m;i++)
      for (int j=0;j<n;j++)
        firstMatrix[i][j] = in.nextInt();

    System.out.println("Enter the elements of Second Matrix:= ");
    for (int i=0;i<m;i++)
      for (int j=0;j<n;j++)
        secondMatrix[i][j]=in.nextInt();

    //declare the elements of both matrices as i & j
    for (int i=0;i<m;i++)
      for (int j=0;j<n;j++)
        sumOfMatrix[i][j]=firstMatrix[i][j] + secondMatrix[i][j];

    System.out.println("Sum of the Two Matrices: ");

    for (int i=0;i<m;i++)
    {
      for (int j=0;j<n;j++) {
        System.out.print(sumOfMatrix[i][j] + " ");
      }
      System.out.println();
    }
  }
}

Screenshot

 

Sample program output

Please enter the number of Rows and Columns of Matrix:=
2 3
Enter the elements of First Matrix:=
3 7 9
6 4 5
Enter the elements of Second Matrix:=
4 7 9
2 1 6
Sum of the Two Matrices:
7 14 18
8 5 11