Plis tell me... which lines need to be in the

Question

1.source files.
2.header file.
3.main file
#include <iostream>
using namespace std;

class MyClass
{
public:
MyClass();
~MyClass();
};

MyClass::MyClass()
{
cout<<"Constructor"<<endl;
}

MyClass::~MyClass()
{
cout<<"Destructor"<<endl;
}

int main() {
MyClass obj;
}

Answer 1

Technically, all of it can exist within main.cpp. However, if you want to sort em:

MyClass.h should contain your class declaration.
MyClass.cpp should include MyClass.h and its corresponding class definition.
main.cpp would include MyClass.h and main() definition.

Answer 2

main file : the main function + include of the header file

header file : include of iostream, using namespace std, declaration of the class and declaration of template parts of the file

source file : include of the header file and definition of none template part of the class