globs in C pointers

AM1SHFURN1TURE · 07-08-2005, 05:43 PM

I have notcied globs used in pointer names both at the start and the beginning of the name.
(ex. *pointer and pointer * )
What is the difference? I haven't found an explanation.

deiussum · 07-08-2005, 06:03 PM

The symbol in front of the pointer is used for "dereferencing" a pointer. That is, accessing the memory that the pointer points to. As an example:

Code:

int i = 10;
// Create a pointer p that points to the memory 
// address of i
int* p = &i;

// Print out the dereferenced value that p points to, 
// this will output 10
printf("%d\n", *p);

// Dereferece p and set the value to 5.  This is 
//accessing the memory of i, so i will be 5 after this
*p = 5;
printf("%d\n", i);

Not quite sure what you mean by the pointer * format. Perhaps you could give a specific example. The only thing I can think of off the top of my head is something like:

int* p;

vs.

int *p;

Both of the above are equivalent.

AM1SHFURN1TURE · 07-08-2005, 06:07 PM

ahh there we go, I was being confused by some stuff I was reading, it kept switching between things like 'int* x' and 'int *x' without giving an explanation of it, thanks - you 'deconfused' me

eddiebaby1023 · 07-09-2005, 05:30 PM

It's confusing to write int* p; since the * binds to p, not to int. Consider:

Code:

int* p, q;
int *p, q;
int *p, *q;

q in the second line is an int not a pointer to int.