class function in .h header file

[mohsen1985]

Hello my friends
I wrote a code to build a matrix class. my code is in the united type and being run as well. I want to separate it into main.cpp , matrix.h and matrix.cpp ones. when I try to do that give me the error "the vector does not name a type"
please someone can do it for me
the best
Mohsen

#include<iostream>
#include<iomanip>
#include<vector>



using namespace std;
class matrix
{
private:
    unsigned rowSize,colSize;
    vector<vector<double> > my_matrix;
public:
    matrix(unsigned ,unsigned, double);
    void print();
};
matrix::matrix(unsigned rowSize,unsigned colSize, double initial):rowSize(rowSize),colSize(colSize)
{
    unsigned M_size = rowSize;
    unsigned N_size = colSize;
    my_matrix.resize(M_size);
    for(unsigned i=0;i<M_size;i++)
    {
        my_matrix[i].resize(N_size,initial);
    }

}
void matrix::print()
{
    for(unsigned i=0;i<rowSize;i++)
    {
        for(unsigned j=0;j<colSize;j++)
        {
          cout<<setw(3)<<my_matrix[i][j];
        }
        cout<<endl;
    }
}


int main()
{
    unsigned M=4;
    unsigned N=4;
    matrix p1(M,N,0.0);
    p1.print();




}

[George P]

PLEASE learn to use code tags, they make reading and commenting on source code much easier.
http://www.cplusplus.com/articles/jEywvCM9/

HINT: you can edit your post and add the code tags.

Which member function are you trying to put into a .cpp file? And what is the error you are getting? Simply saying you are getting an error doesn't help us to help you.

[keskiverto]

#ifndef matrix_h
#define matrix_h

#include <vector> // this is the only thing we depend on in this header

class matrix
{
private:
    std::vector<std::vector<double> > my_matrix;
public:
    matrix(unsigned ,unsigned, double);
    void print() const;
};
#endif 

#include <iostream>
#include <iomanip>
#include "matrix.h"

// The vector has useful constructors
matrix::matrix( unsigned rowSize,unsigned colSize, double initial )
: my_matrix(rowSize, std::vector<double>(colSize, initial))
{
}

void matrix::print() const
{
    for ( auto& row : my_matrix )
    {
        for ( double x : row )
        {
          std::cout << std::setw(3) << x;
        }
        std::cout << '\n';
    }
}

#include "matrix.h" // this is the only thing we depend on in main.cpp

int main()
{
    unsigned M=3;
    unsigned N=4;
    matrix p1(M,N,0.0);
    p1.print();
}

However, why use 2D, when you can use 1D:

class matrix
{
private:
    unsigned rowSize,colSize;
    vector<double> my_matrix;
};

matrix::matrix( unsigned rowSize,unsigned colSize, double initial )
: rowSize(rowSize), colSize(colSize),
  my_matrix( rowSize * colSize, initial )
{
}

void matrix::print()
{
    for (unsigned row=0; row<rowSize; ++row )
    {
        for (unsigned col=0; col<colSize; ++col )
        {
          std::cout << std::setw(3) << my_matrix[ row*colSize + col ];
        }
        std::cout << '\n';
    }
}

[mohsen1985]

thank u keskiverto
but your code give me error in code block too
the same error as mine code

||=== Build file: "no target" in "no project" (compiler: unknown) ===|
C:\Users\f\Documents\main.o:main.cpp|| undefined reference to `matrix::matrix(unsigned int, unsigned int, double)'|
C:\Users\f\Documents\main.o:main.cpp|| undefined reference to `matrix::print() const'|
||error: ld returned 1 exit status|
||=== Build failed: 3 error(s), 0 warning(s) (0 minute(s), 1 second(s)) ===|

[jlb]

Build file: "no target" in "no project" (compiler: unknown)

That "no project" is probably your problem. You need to create a project and add all the files to that project, then compile that project.

[keskiverto]

That is a linker error. Linker should combine object codes to an executable, but it was not given all objects. Both main.cpp and matrix.cpp has to be in the build.