C Programming - Pointers - Discussion

q=(int**)&p // Typecasting.

i initial value is Zero 0 because Global variable.

@All.

i is a global variable and it is uninitialized so it would be stored in a .bss segment so by default the value of i would be zero.

Default value of global variable is 0.

Default value of global variable is set to 0 (zero).

#include<stdio.h>

void fun(void *p);
int i; // global variable

int main()
{
void *vptr; // void poniter is created hear
vptr = &i; // pointer vptr store the address of variable i
fun(vptr); // call to the function fun with passing pointer variable vptr
return 0;
}
void fun(void *p) // function fun with one pointer variable p to store the address of vptr
{
int **q; // hear is create pointer of pointer to store the address of another pointer variable
q = (int**)&p; // hear p is an void pointer it type cast to the integer pointer q is and integer pointer hear
printf("%d\n", **q); // hear print value store in pointer q.
}