&* Operator in C

Question

#include <stdio.h>

int main()
{
    int a=20;
    int *ptr=&a;
    int x=a;
    printf ("%p\n",&*ptr);
    printf ("%p\n",&a);
    return 0;
}

Why both printf() line printing the same address value??

Answer 1

In the first printf, Address of operator (&) and pointer operator (*) cancel the effect of each other leading to printing the address in ptr which contains the address of a

In the second printf, it is simply printing the address of a

So these two results in same value

Answer 2

The associativity of * and & in operator precedence table is right to Left, this means when we say “&*ptr” this means we first dereference the pointer ptr to reach “a” and then print the address.

Therefore we get both the print statements equal.

Answer 3

*ptr = a = &a that’s why both values are same.