how to print value which pointer member pointing to in C

Question

I have a struct

struct c
{
    int *id;
    int type;   

} obj;

how to print what obj.id pointing to? and also point obj->id to some int variable

I tried

printf("%p\n",obj.id);

but above is printing some address

and

printf("%d\n",obj.id);

in above compiler gives warning

format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘int *’

Answer 1

Since obj.id is a pointer to an int (an int* ) you need to dereference it (using the * operator).

Full example:

#include <stdio.h>

struct c {
    int *id;
    int type;   
} obj;

int main() {
    int x = 10;
    obj.id = &x;
    printf("%d\n", *obj.id);
}

Answer 2

You need to dereference the pointer:

printf("%d\n",*(obj.id));