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C++ program to find the multiplication of two matrices using class

Given two matrices, we have to multiply them using the class and object approach.
Submitted by Shubh Pachori, on August 06, 2022

Problem statement

Given two matrices, we have to multiply them using the class and object approach.

Example:

Input: 
Enter Matrix A
Enter x[0][0] : 1
Enter x[0][1] : 2
Enter x[1][0] : 3
Enter x[1][1] : 4
Enter Matrix B
Enter x[0][0] : 4
Enter x[0][1] : 3
Enter x[1][0] : 2
Enter x[1][1] : 1

Matrix A:
1 2 
3 4 

Matrix B:
4 3 
2 1 

Output: 
Addition of A and B matrix
8 5
20 13

C++ code to find the multiplication of two matrices using class and object approach

#include <iostream>
using namespace std;

// create a class
class Matrix {
  // private data members
 private:
  int x[10][10];
  int row, col;

  // public functions
 public:
  // getMatrix() function to insert matrix
  void getMatrix(int r, int c) {
    // initializing a matrix type variable
    Matrix M1;

    // copying value of parameters in the data members
    row = r;
    col = c;

    // nested for loop for insertion of matrix
    for (int i = 0; i < row; i++) {
      for (int j = 0; j < col; j++) {
        cout << "Enter x[" << i << "][" << j << "] : ";
        cin >> x[i][j];
      }
    }
  }

  // putMatrix() function to print the matrix
  void putMatrix() {
    for (int i = 0; i < row; i++) {
      for (int j = 0; j < col; j++) {
        cout << x[i][j] << " ";
      }
      cout << "\n";
    }
  }

  // multiply() function to perform multiplication of two matrix
  Matrix multiply(Matrix M2) {
    // initializing a Matrix type variable
    Matrix M;

    // copying the value of parameters in the data members
    M.row = row;
    M.col = col;

    // nested for loop to multiply two matrices
    for (int i = 0; i < row; i++) {
      for (int j = 0; j < col; j++) {
        M.x[i][j] = 0;
        for (int k = 0; k < col; k++) {
          M.x[i][j] = M.x[i][j] + ((x[i][k]) * (M2.x[k][j]));
        }
      }
    }

    // returning the resulted matrix
    return (M);
  }
};

int main() {
  // creating objects
  Matrix M1, M2, M3;

  // inserting matrix using getMatrix() function
  cout << "Enter Matrix A\n" << endl;
  M1.getMatrix(2, 2);

  cout << "\nEnter Matrix B\n" << endl;
  M2.getMatrix(2, 2);

  // printing the matrix using putMatrix() function
  cout << "\nMatrix A:" << endl;
  M1.putMatrix();

  cout << endl;

  cout << "Matrix B:" << endl;
  M2.putMatrix();

  // calling multiply() function to add two matrix
  M3 = M1.multiply(M2);
  cout << "\nMultiply of A and B matrix\n" << endl;

  // printing the resulted matrix
  M3.putMatrix();
  return 0;
}

Output

Enter Matrix A

Enter x[0][0] : 22
Enter x[0][1] : 33
Enter x[1][0] : 44
Enter x[1][1] : 55

Enter Matrix B

Enter x[0][0] : 66
Enter x[0][1] : 77
Enter x[1][0] : 88
Enter x[1][1] : 99

Matrix A:
22 33 
44 55 

Matrix B:
66 77 
88 99 

Multiply of A and B matrix

4356 4961 
7744 8833

Explanation

In the above code, we have created a class Matrix, three int type data members x[10][10], row, and col to store the matrix, row, and column, and public member functions getMatrix(), putMatrix() and multiply() to insert, print and multiply matrices.

In the main() function, we are creating an object M1, M2, and M3 of class Matrix, reading matrices given by the user using getMatrix() function, and finally calling the multiply() member function to multiply the given matrices. The multiply() function contains the logic to multiply the given matrices and printing the result.

C++ Class and Object Programs (Set 2) »