Use pointer as function parameter : Function Parameter « Function « C Tutorial





#include <stdio.h>

int change(int* pnumber);              /* Function prototype              */

int main(void)
{
  int number = 10;
  int *pnumber = &number;
  int result = 0;        

  result = change(pnumber);
  printf("\nIn main, result = %d\tnumber = %d", result, number);
  return 0;
}

int change(int *pnumber)
{
  *pnumber *= 2;
  printf("\nIn function change, *pnumber = %d\n", *pnumber );

  return *pnumber;
}
In function change, *pnumber = 20
     
     In main, result = 20    number = 20










8.5.Function Parameter
8.5.1.Parameter passing
8.5.2.Call by reference
8.5.3.Pass variables to function
8.5.4.Use pointer as function parameter
8.5.5.Cube a variable using call-by-value
8.5.6.Cube a variable using call-by-reference with a pointer argument