Pointer incrementation

[newbie30]

Just after confusing myself on it and wrecking my head:

int x =6;
int *p=&x

printf("%d", (*p+6))   //gives me 12;
printf("%d", *p)  //should give 12 also??

if i did:
printf("%d", (*p+=))   //gives me 7 should it?;

[Tom Bombadil]

I am just a beginner at C so perhaps this is irrelevant.

int x =6;
int *p=&x

should you not initialise the pointer like this:

int x = 6;
int *p;
p = &x;

[Elysia]

printf("%d", *p) //should give 12 also??

Why should it give you 12?

if i did:
printf("%d", (*p+=)) //gives me 7 should it?;

+= what?

I am just a beginner at C so perhaps this is irrelevant.

int x =6;
int *p=&x

should you not initialise the pointer like this:

int x = 6;
int *p;
p = &x;

It doesn't matter how you initialize the pointer.

[anon]

Instead of asking about code that is obviously mistyped and couldn't possibly produce any output at all, why not post the real code that gives you this output.

#include <stdio.h>

int main(void)
{
    int i = 6;
    int* p = &i;
    
    printf("%d\n", *p + 6); /* 12 */
    printf("%d\n", *p);     /* 6 */
    printf("%d\n", ++*p);   /* 7  NB! *++p would be a serious error */
    printf("%d\n", *p);     /* 7 */
    return 0;
}

[BEN10]

Just after confusing myself on it and wrecking my head:

int x =6;
int *p=&x

printf("%d", (*p+6))   //gives me 12;
printf("%d", *p)  //should give 12 also??

if i did:
printf("%d", (*p+=))   //gives me 7 should it?;

p is a pointer which points to x. Now *p will give the value of x, and *p+6 will give x+6 which is nothing but 12. Again *p is same as x thus 2nd printf prints 6 not 12.
For the 3rd printf I'm assuming you meant *p++(forgot the shift key), since ++ and * have the same precedence and right to left associativity thus p++ is done first and then the value at that address which is nothing but value at the address where p was pointing, thus printing 6. But now p points to a different address, so a 4th printf will give *p=some garbage value.

[robwhit]

    printf("%d\n", ++*p);   /* 7  NB! *++p would be a serious error */

what's NB?

[tabstop]

NB: nota bene