C++ header files

My header file looks like this:

#ifndef PPMIMAGE_H_ #define PPMIMAGE_H_ class PpmImage{ public: void readImage(char* data); void setRows(int row){ rows = row; } void setCols(int col){ cols = col; } void setDataArray(int size){ data = new char[size]; } int getRows(){ return rows; } int getCols(){ return cols; } char* getDataArray(){ return data; }

private: int rows; int cols; char* data; }; #endif

Now, I need to implement readImage() function in my .cpp file which now only contains the main method:

#include "ppmImage.h"

using namespace std;

int main(int argc, char** argv) {

PpmImage image; image.setRows(-1); image.setCols(-1); int rows = image.getRows(); int cols = image .getCols();

}

how to implement the readImage() function in my .cpp?