my program:

BOX.H
-------
#ifndef BOX_H
#define BOX_H

class Box
{
private:
int length;
int width;

public:
//constructor
Box();

//methods
void setValue(int length,int width);
int getArea();

//destructor
~Box();
};

#endif
--------
************************

BOX.cpp
--------
#include "box.h"

//constructor
Box::Box()
{
length = 8;
width = 8;
}

//setter
void Box::setValue(int length,int width)
{
Box::length = length;
Box::width = width;
}

//getter
int Box::getArea()
{
return (Box::length * Box::width);
}

//destructor
Box::~Box()
{
length = 0;
width = 0;
}
---------
****************************

BoxMain.cpp
---------
#include <iostream>
#include "box.h"

int main()
{
Box small, medium, large;

small.setValue(5,7);

large.setValue(15,20);

//display results
std::cout << "\nThe small box area is " << small.getArea();
std::cout << "\nThe medium box area is " << medium.getArea();
std::cout << "\nThe large box area is " << large.getArea() << std::endl;

return 0;
}
----------
*****************************

My question:

As you can see in the methods, i have declared the variables inside the setter methods same as the private objects in the class.
My aim was to be able to use same name as you can see.
If i DO NOT prefix the private data with Box:: as shown below

//setter
void Box::setValue(int length,int width)
{
length = length;
width = width;
}
i DO NOT get the desired output since the compiler is confused.

But if i prefix the private data with the Box:: as shown below:

//setter
void Box::setValue(int length,int width)
{
Box::length = length;
Boxx::width = width;
}
the program works fine!

So, i want to ask if the way i did is correct or not?

Thanks for ur attention!

Kind Regards,
wakish