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Hi, i'm learning the OOP and C++ at home. Now I'm at the Constructor - destructor stuff, and while going thru some exercises i got an error. Now please look at the code and help me. Thanks! :kosta:

Code:

#include <iostream>

#include <conio.h>

#include <cstring>

using namespace std;



class ZnakovniNiz {

public:



        char *pok;



        ZnakovniNiz(char *p): pok(new char[strlen(p)+1]) {

 *int i;

 *for(i=strlen(p)+1;i>=0;i--)

 *        *(pok+i)=*(p+i);

        };

        ZnakovniNiz(const ZnakovniNiz &zn): pok(new char[strlen(zn.pok)+1]) {

 *int i;

 *for(i=strlen(zn.pok)+1;i>=0;i--)

 *        *(pok+i)=*(zn.pok+i);

        };

        ~ZnakovniNiz() { delete [] pok;        };

};



int main(void)

{

        char strl[]="Tko je taj pokemon?";



        ZnakovniNiz PrviNiz(strl);

        cout<<strl<<endl<<PrviNiz.pok<<endl;



        ZnakovniNiz DrugiNiz(PrviNiz);

        cout<<DrugiNiz.pok<<endl;



        *(DrugiNiz.pok+3)='%';

        cout<<DrugiNiz.pok<<endl;

        cout<<PrviNiz.pok<<endl;



        getch();



        return 0;

}

The exercise is about an array of characters, there are 2 copy constructors for allocating a new memory and then copying needed stuff, and a destructor for deleting that memory.
At the end of execution i get this problem:
http://img80.echo.cx/img80/5581/probi0eu.th.gif

I also know that the program worked fine before creating a destructor. :wall:

:cheers:

the loops you use to copy a string are flawed.

for(i=strlen(p);i=0;i--)

Then it will be allright.

Quote:

Originally posted by Data@Apr 26 2005, 07:38 PM
the loops you use to copy a string are flawed.

for(i=strlen(p);i=0;i--)

Then it will be allright.

Code:

for(i=strlen(p);i>=0;i--)

 *        *(pok+i)=*(p+i);

Cool... not cool no I fell like a dumbass... :cry:

Thanks Data! :ok: :kosta:

Now you have honour off closeing this topic.

... :wall:

as you allready include cstring...
why not do a strcpy(pok,p);

Oh well That's outside the scope of this thread.

Quote:

Originally posted by Data@Apr 26 2005, 08:25 PM
as you allready include cstring...
why not do a strcpy(pok,p);

Oh well That's outside the scope of this thread.

I could but isn't this way faster??? :blink:

I doubt it.
the libc functions are quite optimized.
(they could have been written in pure asm).

Don't try to reinvent the wheel.
as there smarter systems for copying a string. like
while ((a[i]=b[i])) i++;

and not to mention that strlen takes computing power as well. (strcpy probably doesn't check for the length.(like that while system.)

Cool, great man....
...so can i PM you if i have another problem.... ???

:blink:

as long as you keep the source that demostrates the problem small and readable.

Quote:

Originally posted by Data@Apr 26 2005, 09:38 PM
as long as you keep the source that demostrates the problem small and readable.

NP, thanks :ok: :cheers: