Why do I say int *p = NULL in the declaration, but p != NULL in the test, why not *p != NULL to match the declaration?

Question

in c++, if we assign a pointer value to NULL ,why dont we check if *p!=NULL and instead p!=NULL?

I found this code in a tutorial.

int *p = NULL;
char *q = NULL;
// ...
if (p!=NULL) cout << *p;

Thanks in advance

Answer 1

The * is doing two different things. When you declare the variable, it means the variable is a pointer. When you use the variable, it means "dereference", that is take the value at the location the pointer is pointing to. Two totally different meanings.