for whom the header files are important?

[yogpjosh]

Hi,

for whom the header files are important?

for the programmer or for the compiler..??
As the programmer very well sees all the private data of a class
through the header file ..but if he tries to access it then the
compiler throws the error..


Thanks and Regards,
Yogesh Joshi

 

[Gianni Mariani]

Hi,

for whom the header files are important?

for the programmer or for the compiler..??
As the programmer very well sees all the private data of a class
through the header file ..but if he tries to access it then the
compiler throws the error..

Header files allow you to create "interfaces" and reusability of code.

As for private data, you can, if you wish, hide all your private
elements in the cpp file.

 

[Kai-Uwe Bux]

for whom the header files are important?

for the programmer or for the compiler..??

The compiler.

As the programmer very well sees all the private data of a class
through the header file ..but if he tries to access it then the
compiler throws the error..

The programmer is supposed to read the documentation/specs. Stuff in the
headers are implementation details.


Best

Kai-Uwe Bux

 

[Salt_Peter]

Hi,

for whom the header files are important?

for the programmer or for the compiler..??
As the programmer very well sees all the private data of a class
through the header file ..but if he tries to access it then the
compiler throws the error..


Thanks and Regards,
Yogesh Joshi

As far as the compiler is concerned, header files don't exist.
That is, until you include them into your source(s).
And nothing stops you from accessing the private parts of a class,
either.
Thats what accessors and public member functions are for.
Compilers generate errors because the declaration of the class is a set
of rules the compiler must obey and enforce.

 

[Signal9]

Hi,

for whom the header files are important?

for the programmer or for the compiler..??
As the programmer very well sees all the private data of a class
through the header file ..but if he tries to access it then the
compiler throws the error..


Thanks and Regards,
Yogesh Joshi

You should read a C++ book please.

 

[yogpjosh]

As far as the compiler is concerned, header files don't exist.
That is, until you include them into your source(s).
And nothing stops you from accessing the private parts of a class,
either.
Thats what accessors and public member functions are for.
Compilers generate errors because the declaration of the class is a set
of rules the compiler must obey and enforce.

Yes..got it..merely seeing the private variables doesn't mean you have
access to that..

Thanks and Regards,
Yogesh Joshi

 

[Salt_Peter]

Yes..got it..merely seeing the private variables doesn't mean you have
access to that..

Thanks and Regards,
Yogesh Joshi

Not neccessarily true.

class N
{
int n;
public:
N() : n(0) { }
void set(int x) { n = x; }
int get() const { return n; }
};

I can see, modify and access the private integer n.

 

[yogpjosh]

Not neccessarily true.

class N
{
int n;
public:
N() : n(0) { }
void set(int x) { n = x; }
int get() const { return n; }
};

I can see, modify and access the private integer n.

sorry ..what I mean to say was..accessing the private variables
directly..i.e without using any member functions..
(I also come across this statement that " getter and setter functions
reveal the internal implementation details of the class and should be
avoided..")

cheers,
Yogesh Joshi

 

[Noah Roberts]

sorry ..what I mean to say was..accessing the private variables
directly..i.e without using any member functions..

You still can, but only if you abuse the system:

N n;
int * n_member = reinterpret_cast<int*>(&n);
n_member = 5;

 

[Gianni Mariani]

Noah Roberts wrote:
....

You still can, but only if you abuse the system:

N n;
int * n_member = reinterpret_cast<int*>(&n);
n_member = 5;

did you mean:

N n;
int & n_member = * reinterpret_cast<int*>(&n);
n_member = 5;

?

 

[yogpjosh]

Noah Roberts wrote:
...

did you mean:

N n;
int & n_member = * reinterpret_cast<int*>(&n);
n_member = 5;

?

but those are the intentional (illegal??) activities of the programmer
..But compiler will complain if the programmer writes

n.n //access denied..

so that means the header files are for compiler..

cheers,
Yogesh Joshi

 

[Salt_Peter]

but those are the intentional (illegal??) activities of the programmer
.But compiler will complain if the programmer writes

n.n //access denied..

so that means the header files are for compiler..

Again, as far as the compiler is concerned, header files don't exist.
Thats why you need to include them into source(s).