C++ Operator Overloading. Please help me with the scalar function of this code.

Question

 C++ Operator Overloading.  Please help me with the scalar function of this code. 

 Matrix<T> Matrix<T>::operator*(const T &scalar) {      

    Operator Overloading   #First-Name Last-Name  TODO - Update your name in this readme.  TODO - Add a badge from travis CI here  ##Problem statement: Overload the operators +,-,* in the class Matrix. Look into the file `Matrix.h` for more details.    ## Files to work on * `Matrix.h` Overload the necesseray Operators * You can also modify `main.cpp` to debug your program. * `README.md` to add your name and badge Please **DO NOT MODIFY** any other files. Modifying any other file will result in penalty to your grade.        ## Exceptions to be thrown Throw the default exception whereever necessary (Incorrect sizes, etc)  ## Matrix Multiplication Order ```  Given the statement: Mat3 = Mat1 * Mat2;  Mat1 ={{1,  3, -3},        {-4, 4, 5},        {-1, 2, 0},        {6,  7, 8}};  Mat2 ={{-2, 9, 3,  1},        {10, 4, 5,  11},        {-1, 2, 12, 0}};  Then Mat3 will be:  Mat3 :{{31, 15,  -18, 34},        {43, -10, 68,  40},        {22, -1,  7,   21},        {50, 98,  149, 83}};  ``` ## Constraints  * The class should support the following types via templates:     * int     * float 

  #include <iostream> #include "Matrix.h"  using namespace std;  int main() {     cout << "Hello, World!" << endl;     Matrix<int> m1(2, 2);      m1.printMatrix();      Matrix<int> m2(4, 4);      m2.printMatrix();       Matrix<int> m3(4, 4);      m3.printMatrix();       Matrix<int> m4 = m2 + m3;      m4.printMatrix();       //twoD is defined in src/Matrix.h      twoD<int> myMatrix = {{2, 2, 2, 2},                           {3, 3, 3, 3},                           {4, 4, 4, 4},                           {5, 5, 5, 5}};       Matrix<int> m5(4, 4, myMatrix);      Matrix<int> m6 = m2 + m5;      m6.printMatrix();      Matrix<int> m7 = m2 * m3;     m7.printMatrix();     

  #pragma once  #include <exception> #include <vector> #include <iostream> #include <vector>  using namespace std;   template<typename T> using twoD = std::vector<std::vector<T>>; //more info on the above: http://stackoverflow.com/a/16861385/3255842  template<class T> class Matrix { private:     int rows;     int cols;     twoD<T> matrix; protected:     void validSizeCheck(int rows, int cols);  public:     Matrix(int rows, int cols);      Matrix(int rows, int cols, twoD<T> newMatrix);      twoD<T> getMatrix();      int getRows();      int getCols();      void operator=(const Matrix<T> &);      Matrix<T> &operator+=(const Matrix<T> &);      Matrix<T> &operator-=(const Matrix<T> &);      Matrix<T> &operator*=(const Matrix<T> &);      Matrix<T> &operator*=(const T &);      /*     friend void operator<<(ostream &os, const Matrix<T> &m) {         for (int i = 0; i < m.rows; i++) {             for (int j = 0; j < m.cols; j++) {                 os << m.matrix[i][j] << " ";             }             os << endl;         }         os << endl;         os << endl;     }      */      void printMatrix();       //T-O-D-O functions are below     Matrix<T> operator+(const Matrix<T> &);      Matrix<T> operator-(const Matrix<T> &);      Matrix<T> operator*(const Matrix<T> &);      Matrix<T> operator*(const T &);  };  template<class T> void Matrix<T>::validSizeCheck(int rows, int cols) {     //DO NOT MODIFY     //This is a helper function for checking invalid size.     if (rows < 1 || cols < 1) {         throw exception();     } }   template<class T> twoD<T> Matrix<T>::getMatrix() {     //DO NOT MODIFY     return matrix; }  template<class T> int Matrix<T>::getRows() {     //DO NOT MODIFY     return rows; }  template<class T> int Matrix<T>::getCols() {     //DO NOT MODIFY     return cols; }   template<class T> Matrix<T>::Matrix(int rows, int cols) : rows(rows), cols(cols) {     //DO NOT MODIFY     validSizeCheck(rows, cols);     matrix.resize(rows);     for (int i = 0; i < rows; i++) {         matrix[i].resize(cols);         for (int j = 0; j < cols; j++) {             matrix[i][j] = 0;             //cout << "Writing: i: " << i << " j: " << j << " val: " << matrix[i][j] << endl;         }     }  }  template<class T> Matrix<T>::Matrix(int rows, int cols, twoD<T> newMatrix) : rows(rows), cols(cols) {     //DO NOT MODIFY     validSizeCheck(rows, cols);     matrix.resize(rows);     for (int i = 0; i < rows; i++) {         matrix[i].resize(cols);         for (int j = 0; j < cols; j++) {             matrix[i][j] = newMatrix[i][j];         }     }   }  template<class T> void Matrix<T>::operator=(const Matrix<T> &rhs) {     //DO NOT MODIFY      if (rows != rhs.rows || cols != rhs.cols) {         //throw exception     }     Matrix<T> newMatrix(rows, cols);      for (int i = 0; i < rows; i++) {         for (int j = 0; j < cols; j++) {             newMatrix.matrix[i][j] = rhs.matrix[i][j];         }     } }  template<class T> Matrix<T> &Matrix<T>::operator+=(const Matrix<T> &rhs) {     //DO NOT MODIFY     *this = *this + rhs;     return *this; }  template<class T> Matrix<T> &Matrix<T>::operator-=(const Matrix<T> &rhs) {     //DO NOT MODIFY     *this = *this - rhs;     return *this; }  template<class T> Matrix<T> &Matrix<T>::operator*=(const Matrix<T> &rhs) {     //DO NOT MODIFY     *this = *this * rhs;     return *this; }  template<class T> Matrix<T> &Matrix<T>::operator*=(const T &rhs) {     //DO NOT MODIFY     *this = *this * rhs;     return *this; }    template<class T> void Matrix<T>::printMatrix() {     for (int i = 0; i < rows; i++) {         for (int j = 0; j < cols; j++) {             cout << matrix[i][j] << " ";         }         cout << endl;     }     cout << endl;     cout << endl; }  

 Matrix<T> Matrix<T>::operator*(const T &scalar) {     //TODO 

      twoD<int> myMulMatrix1 = {             {1,  3, -3},             {-4, 4, 5},             {-1, 2, 0},             {6,  7, 8}     };      twoD<int> myMulMatrix2 = {             {-2, 9, 3,  1},             {10, 4, 5,  11},             {-1, 2, 12, 0}     };      Matrix<int> mulMat1(4, 3, myMulMatrix1);     Matrix<int> mulMat2(3, 4, myMulMatrix2);      Matrix<int> mulMat3 = mulMat1 * mulMat2;      mulMat3.printMatrix();      //cout << mulMat3;      return 0; 

Explanation / Answer

Here is the code for the scalar function

template<class T>

Matrix<T> Matrix<T>::operator*(const T &scalar) {

//TODO

   for(int i = 0; i < rows; ++i)

   {

       for(int j=0; j<cols; j++)

           matrix[i][j] *= scalar;

   }

   return *this;

}

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