I am trying to access the plum class but code blocks gives error that is undefined reference to `plum::plum()......kindly help


Error
=== Build: Debug in pointers to access class (compiler: GNU GCC Compiler) ===
In function main();
D:\C++\pointers to access class\main.cpp7undefined reference to `plum::plum()'
D:\C++\pointers to access class\main.cpp8undefined reference to `plum::print1()'
=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 3 second(s)) ===




main.cpp is
#include <iostream>
#include "plum.h"
using namespace std;


int main()
{
   plum PO;
   PO.print1();
}


plum.cpp is
#include "plum.h"
#include <iostream>
using namespace std;


plum::plum()
{


}


void plum::print1(){
cout << "access plum class using object" << endl;
}


void plum::print2(){
cout << "access plum class using pointers" << endl;
}


plum.h is
#ifndef PLUM_H
#define PLUM_H




class plum
{
    public:
        plum();
        void print1();
        void print2();
};


#endif // PLUM_H