Page 109 - 6437

Value of var = 3000

Value available at *ptr = 3000

Value available at **pptr = 3000

Passing Pointers to Functions
C programming allows passing a pointer to a function. To do so, simply declare the
function parameter as a pointer type.
Following is a simple example where we pass an unsigned long pointer to a function and
change the value inside the function which reflects back in the calling function:

#include <stdio.h>
#include <time.h>

void getSeconds(unsigned long *par);

int main ()

{
unsigned long sec;

getSeconds( &sec );

/* print the actual value */

printf("Number of seconds: %ld\n", sec );

return 0;
}

void getSeconds(unsigned long *par)
{
/* get the current number of seconds */

*par = time( NULL );
return;

}

112