Matrix

package com.company;

public class Matrix {
    public static void main(String[] args) {
        int sum = 0;
        int a[][] = {{1, 3, 4}, {2, 4, 3}, {3, 4, 5}};
        int b[][] = {{1, 3, 4}, {2, 4, 3}, {1, 2, 4}};
        System.out.println("The first matrix is : ");
        for (int i = 0; i < a.length; i++) {
            for (int j = 0; j < a[0].length; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }
        System.out.println("The second matrix is : ");
        for (int i = 0; i < b.length; i++) {
            for (int j = 0; j < b[0].length; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }
        int matrix[][] = new int[3][3];
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                matrix[i][j] = a[i][j] + b[i][j];
            }
        }
        System.out.println("The addition of two matrices is : ");
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                System.out.print(matrix[i][j] + " ");
            }
            System.out.println();
        }
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                for (int k = 0; k < 3; k++) {
                    sum = sum + (a[i][k] * b[k][j]);
                }
                matrix[i][j] = sum;
                sum = 0;
            }
        }
        System.out.println("The multiplication of two matrices is : ");
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                System.out.print(matrix[i][j] + " ");
            }
            System.out.println();
        }
    }
}