Function(char ch,int y,...) how to use this kinda function?

The parameters can be any data types. You know how to use it. Have you ever used the following function?

int printf(const char *format, ...);

Hi..
yes i know printf..
but how do i build my own unction like this??

Thanks.

Hi..
yes i know printf..
but how do i build my own unction like this??

Thanks.

Hi,

This sample program may give u some idea. compile and run it.

#include <iostream.h>

int funct(char ch,int x,...);

void main()
{
      funct('f',1,200,3);
      return;
}

int funct(char cc,int p,...)
{
      int x = p;
      int y = *(&p+1);
      int z = *(&p+2);

      cout << "First Arg = " << cc << endl;
      cout << "Second Arg = " << x << endl;
      cout << "Third Arg = " << y << endl;
      cout << "Fourth Arg = " << z << endl;
      return 1;
}

Hope that gives U some idea on how to use such functions.

Thanks...
it works.. can you give me some idea how to loop around and collect all the passed vars?

Hi. ok thanks it work ok but i have one problem:
this is my code:

void CMyClass::Func(int y,...)
{
int Sum=0;
  va_list pStrList;
  va_start(pStrList,y);
  int u=0;
 
  Sum+=y ;

  while((Sum+=va_arg(pStrList,int))!= NULL)
      u++;

  va_end(pStrList);
}
i did it just for testing.. and i get never ending loop..
it never reaches NULL..
why?

Please email me the answer to:
kishk91@hotmail.com
Thanks
kishk91

Hi,

If you want to get NULL, the last parametor to the function must be NULL.

Generaly you can handle such function in two ways:

1) Give another parameter telling the number of parameters, then loop this number times.

2) Set the last parameter to be out-of-renge (like NULL) value, and loop till you rich it.

Thanks for your help...
its ok now..

>but how do i build my own unction like this??

Your original question says "i would like to understand how to use it..".

Hi chensu...
ok imsorry i wasnt explaining my self correctly...

no heart feelings?

No problem. Next time, in order to get quick and good answer, you should state the question clearly.

I got it ...

;-)