A PROGRAM SHOWING DISADVANTAGE OF POINTER ON PASSING AS ARG

 1 /*A program showing disadvantage of ptr.....*/

  2 #include<stdio.h>

  3 #include<stdlib.h>

  4 int main()

  5 {

  6 int ret;

  7 int *ptr;

  8 ptr=malloc(4);

  9 printf("ptr=%d\n",ptr);

 10 ret=fun(ptr);

 11 printf("value of ptr=%d\n",*ptr);

 12 return 0;

 13 }

 14 int fun(char* ptr)

 15 {

 16 int i=17;

 17 printf("ptr=%d\n",ptr);

 18 ptr=&i;////...........*ptr=i; can be used no doubt

 19 printf("ptr=%d\n",ptr);

 20

 21 return 0;

 22 }

 23

 24 OUT/P

:ptr=149381128

ptr=149381128

ptr=-1078390852

value of ptr=0

ADDRESS OF POINTER IS GONE CHANGED IN CALLED FUNCTION....SO VALUE IS NOT ASSIGNED TO ORIGIONAL PTR.....SO IN MAIN AFTER CALLING PTR...WE ARE NOT ABLE TO  GET VALUE FROM PTR