C ++中函数的多重定义

Question

I am having a very unusual problem:

I keep getting multiple definition of functions in my class.

This is my main .cpp

#include <iostream>
#include "Calculation.cpp"

using namespace std;

int main()
{
    cout << "Hello world!" << endl;
    return 0;
}

this is my class .h

#ifndef CALCULATION_H_INCLUDED
#define CALCULATION_H_INCLUDED

class Calculation
{
  public:
  Calculation();
  private:

};
#endif // CALCULATION_H_INCLUDED

this is my implementation file .cpp

#include "Calculation.h"

Calculation::Calculation()
{

}

Please help me; I have tried to create a new project but that didn't help.

All help is appreciated.

Answer 1

make your main.cpp like :

#include <iostream>
#include "Calculation.h"  // not Calculation.cpp

using namespace std;

int main()
{
    cout << "Hello world!" << endl;
    return 0;
}

Answer 2

You have to include your Calculation.h in th main.cpp and you have to compile it as follows,

  g++ main.cpp Calculate.cpp -o main -I<path for your .h file>

main.cpp

  #include<iostream>
  #include "Calculation.h"
  //using namespace std; // Avoid this, always to use std::cout .. etc on place

  int main()
  {
      Calculation c; //Creating the object of Calculation class
      std::cout<<"Hello World!"<<std::endl;
      return 0;
  }