The operator used to get value at address stored in a pointer variable is

The operator used to get value at address stored in a pointer variable is

2) What will be the output of the following C code?

 #include <stdio.h>
 int main()
 {
     int *ptr, a = 10;
     ptr = &a;
     *ptr += 1;
     printf("%d,%d/n", *ptr, a);
 }

3) If a variable is a pointer to a structure, then which of the following operator is used to access data members of the structure through the pointer variable?

4) What will be the output of the program If the integer is 4bytes long?

 #include<stdio.h>
 int main()
 {
     int ***r, **q, *p, i=8;
     p = &i;
     q = &p;
     r = &q;
     printf("%d, %d, %d\n", *p, **q, ***r);
     return 0;
 }

5) What is (void*)0?